Histone demethylase inhibitors

ABSTRACT

The present invention relates generally to compositions and methods for treating cancer and neoplastic disease. Provided herein are substituted pyrrolopyridine derivative compounds and pharmaceutical compositions comprising said compounds. The subject compounds and compositions are useful for inhibition of histone demethylase. Furthermore, the subject compounds and compositions are useful for the treatment of cancer, such as prostate cancer, breast cancer, bladder cancer, lung cancer and/or melanoma and the like.

CROSS-REFERENCE

This application claims the benefit of U.S. Provisional Application 62/051,850, filed Sep. 17, 2014, which is incorporated herein by reference in its entirety.

BACKGROUND

A need exists in the art for an effective treatment of cancer and neoplastic disease.

BRIEF SUMMARY OF THE INVENTION

Provided herein are substituted pyrrolopyridine derivative compounds and pharmaceutical compositions comprising said compounds. The subject compounds and compositions are useful for inhibition histone demethylase. Furthermore, the subject compounds and compositions are useful for the treatment of cancer, such as prostate cancer, breast cancer, bladder cancer, lung cancer and/or melanoma and the like. The substituted pyrrolopyridine derivative compounds described herein are based upon a disubstituted pyrrolo[3,2-b]pyridine ring system bearing at the 7-position a carboxylic acid or bioisostere thereof, and a second substituent at the 2-position. The 2-position substituent, in various embodiments, is selected from a bicyclic heteroaryl group.

One embodiment provides a compound having the structure of Formula (I),

or a pharmaceutically acceptable salt thereof,

-   wherein, -   R¹ is hydrogen or alkyl; -   R² is hydrogen, halogen or alkyl; -   G is

-   n is 0, 1, or 2; -   R³ is alkyl, carbocyclyl, carbocyclylalkyl, heterocyclyl, or     heterocyclylalkyl; -   R⁴ is halogen, alkyl, alkoxy, carbocyclyl, heterocyclyl, aryl,     heteroaryl, or X—R⁵;     -   wherein:     -   X is —(C₁-C₆)alkylene-, —O—, —S—, or —NR¹—; and     -   R⁵ is carbocyclyl, heterocyclyl, aryl, or heteroaryl.

One embodiment provides a pharmaceutical composition comprising a compound of Formula (I), or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient.

One embodiment provides a method for inhibiting a histone demethylase enzyme comprising contacting the histone demethylase enzyme with a compound of Formula (I).

One embodiment provides a method for treating cancer in subject in need thereof comprising administering to the subject a composition comprising a compound of Formula (I) or a pharmaceutically acceptable salt thereof.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

DETAILED DESCRIPTION OF THE INVENTION

As used herein and in the appended claims, the singular forms “a,” “and,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “an agent” includes a plurality of such agents, and reference to “the cell” includes reference to one or more cells (or to a plurality of cells) and equivalents thereof known to those skilled in the art, and so forth. When ranges are used herein for physical properties, such as molecular weight, or chemical properties, such as chemical formulae, all combinations and subcombinations of ranges and specific embodiments therein are intended to be included. The term “about” when referring to a number or a numerical range means that the number or numerical range referred to is an approximation within experimental variability (or within statistical experimental error), and thus the number or numerical range may vary between 1% and 15% of the stated number or numerical range. The term “comprising” (and related terms such as “comprise” or “comprises” or “having” or “including”) is not intended to exclude that in other certain embodiments, for example, an embodiment of any composition of matter, composition, method, or process, or the like, described herein, may “consist of” or “consist essentially of” the described features.

Definitions

As used in the specification and appended claims, unless specified to the contrary, the following terms have the meaning indicated below.

“Amino” refers to the —NH₂ radical.

“Cyano” refers to the —CN radical.

“Nitro” refers to the —NO₂ radical.

“Oxa” refers to the —O— radical.

“Oxo” refers to the ═O radical.

“Thioxo” refers to the ═S radical.

“Imino” refers to the ═N—H radical.

“Oximo” refers to the ═N—OH radical.

“Hydrazino” refers to the ═N—NH₂ radical.

“Alkyl” refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, containing no unsaturation, having from one to fifteen carbon atoms (e.g., C₁-C₁₅ alkyl). In certain embodiments, an alkyl comprises one to thirteen carbon atoms (e.g., C₁-C₁₃ alkyl). In certain embodiments, an alkyl comprises one to eight carbon atoms (e.g., C₁-C₈ alkyl). In other embodiments, an alkyl comprises one to five carbon atoms (e.g., C₁-C₅ alkyl). In other embodiments, an alkyl comprises one to four carbon atoms (e.g., C₁-C₄ alkyl). In other embodiments, an alkyl comprises one to three carbon atoms (e.g., C₁-C₃ alkyl). In other embodiments, an alkyl comprises one to two carbon atoms (e.g., C₁-C₂ alkyl). In other embodiments, an alkyl comprises one carbon atom (e.g., C₁ alkyl). In other embodiments, an alkyl comprises five to fifteen carbon atoms (e.g., C₅-C₁₅ alkyl). In other embodiments, an alkyl comprises five to eight carbon atoms (e.g., C₅-C₈ alkyl). In other embodiments, an alkyl comprises two to five carbon atoms (e.g., C₂-C₅ alkyl). In other embodiments, an alkyl comprises three to five carbon atoms (e.g., C₃-C₅ alkyl). In other embodiments, the alkyl group is selected from methyl, ethyl, 1-propyl (n-propyl), 1-methylethyl (iso-propyl), 1-butyl (n-butyl), 1-methylpropyl (sec-butyl), 2-methylpropyl (iso-butyl), 1,1-dimethylethyl (tert-butyl), 1-pentyl (n-pentyl). The alkyl is attached to the rest of the molecule by a single bond. Unless stated otherwise specifically in the specification, an alkyl group is optionally substituted by one or more of the following substituents: halo, cyano, nitro, oxo, thioxo, imino, oximo, trimethylsilanyl, —OR^(a), —SR^(a), —OC(O)—R^(a), —N(R^(a))₂, —C(O)R^(a), —C(O)OR^(a), —C(O)N(R^(a))₂, —N(R^(a))C(O)OR^(a), —OC(O)— N(R^(a))₂, —N(R^(a))C(O)R^(a), —N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —S(O)_(t)OR^(a) (where t is 1 or 2), —S(O)_(t)R^(a) (where t is 1 or 2) and —S(O)_(t)N(R^(a))₂ (where t is 1 or 2) where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl.

“Alkoxy” refers to a radical bonded through an oxygen atom of the formula —O-alkyl, where alkyl is an alkyl chain as defined above.

“Alkenyl” refers to a straight or branched hydrocarbon chain radical group consisting solely of carbon and hydrogen atoms, containing at least one carbon-carbon double bond, and having from two to twelve carbon atoms. In certain embodiments, an alkenyl comprises two to eight carbon atoms. In other embodiments, an alkenyl comprises two to four carbon atoms. The alkenyl is attached to the rest of the molecule by a single bond, for example, ethenyl (i.e., vinyl), prop-1-enyl (i.e., allyl), but-1-enyl, pent-1-enyl, penta-1,4-dienyl, and the like. Unless stated otherwise specifically in the specification, an alkenyl group is optionally substituted by one or more of the following substituents: halo, cyano, nitro, oxo, thioxo, imino, oximo, trimethylsilanyl, —OR^(a), —SR^(a), —OC(O)—R^(a), —N(R^(a))₂, —C(O)R^(a), —C(O)OR^(a), —C(O)N(R^(a))₂, —N(R^(a))C(O)OR^(a), —OC(O)— N(R^(a))₂, —N(R^(a))C(O)R^(a), —N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —S(O)_(t)OR^(a) (where t is 1 or 2), —S(O)_(t)R^(a) (where t is 1 or 2) and —S(O)_(t)N(R^(a))₂ (where t is 1 or 2) where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl.

“Alkynyl” refers to a straight or branched hydrocarbon chain radical group consisting solely of carbon and hydrogen atoms, containing at least one carbon-carbon triple bond, having from two to twelve carbon atoms. In certain embodiments, an alkynyl comprises two to eight carbon atoms. In other embodiments, an alkynyl has two to four carbon atoms. The alkynyl is attached to the rest of the molecule by a single bond, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, and the like. Unless stated otherwise specifically in the specification, an alkynyl group is optionally substituted by one or more of the following substituents: halo, cyano, nitro, oxo, thioxo, imino, oximo, trimethylsilanyl, —OR^(a), —SR^(a), —OC(O)—R^(a), —N(R^(a))₂, —C(O)R^(a), —C(O)OR^(a), —C(O)N(R^(a))₂, —N(R^(a))C(O)OR^(a), —OC(O)— N(R^(a))₂, —N(R^(a))C(O)R^(a), —N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —S(O)_(t)OR^(a) (where t is 1 or 2), —S(O)_(t)R^(a) (where t is 1 or 2) and —S(O)_(t)N(R^(a))₂ (where t is 1 or 2) where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl.

“Alkylene” or “alkylene chain” refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing no unsaturation and having from one to twelve carbon atoms, for example, methylene, ethylene, propylene, n-butylene, and the like. The alkylene chain is attached to the rest of the molecule through a single bond and to the radical group through a single bond. The points of attachment of the alkylene chain to the rest of the molecule and to the radical group can be through one carbon in the alkylene chain or through any two carbons within the chain. In certain embodiments, an alkylene comprises one to eight carbon atoms (e.g., C₁-C₈ alkylene). In other embodiments, an alkylene comprises one to five carbon atoms (e.g., C₁-C₅ alkylene). In other embodiments, an alkylene comprises one to four carbon atoms (e.g., C₁-C₄ alkylene). In other embodiments, an alkylene comprises one to three carbon atoms (e.g., C₁-C₃ alkylene). In other embodiments, an alkylene comprises one to two carbon atoms (e.g., C₁-C₂ alkylene). In other embodiments, an alkylene comprises one carbon atom (e.g., C₁ alkylene). In other embodiments, an alkylene comprises five to eight carbon atoms (e.g., C₅-C₈ alkylene). In other embodiments, an alkylene comprises two to five carbon atoms (e.g., C₂-C₅ alkylene). In other embodiments, an alkylene comprises three to five carbon atoms (e.g., C₃-C₅ alkylene). Unless stated otherwise specifically in the specification, an alkylene chain is optionally substituted by one or more of the following substituents: halo, cyano, nitro, oxo, thioxo, imino, oximo, trimethylsilanyl, —OR^(a), —SR^(a), —OC(O)—R^(a), —N(R^(a))₂, —C(O)R^(a), —C(O)OR^(a), —C(O)N(R^(a))₂, —N(R^(a))C(O)OR^(a), —OC(O)— N(R^(a))₂, —N(R^(a))C(O)R^(a), —N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —S(O)_(t)OR^(a) (where t is 1 or 2), —S(O)_(t)R^(a) (where t is 1 or 2) and —S(O)_(t)N(R^(a))₂ (where t is 1 or 2) where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl.

“Aryl” refers to a radical derived from an aromatic monocyclic or multicyclic hydrocarbon ring system by removing a hydrogen atom from a ring carbon atom. The aromatic monocyclic or multicyclic hydrocarbon ring system contains only hydrogen and carbon from five to eighteen carbon atoms, where at least one of the rings in the ring system is fully unsaturated, i.e., it contains a cyclic, delocalized (4n+2) π-electron system in accordance with the Hückel theory. The ring system from which aryl groups are derived include, but are not limited to, groups such as benzene, fluorene, indane, indene, tetralin and naphthalene. Unless stated otherwise specifically in the specification, the term “aryl” or the prefix “ar-” (such as in “aralkyl”) is meant to include aryl radicals optionally substituted by one or more substituents independently selected from alkyl, alkenyl, alkynyl, halo, fluoroalkyl, cyano, nitro, optionally substituted aryl, optionally substituted aralkyl, optionally substituted aralkenyl, optionally substituted aralkynyl, optionally substituted carbocyclyl, optionally substituted carbocyclylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyl, —R^(b)—OR^(a), —R^(b)—OC(O)—R^(a), —R^(b)—OC(O)—OR^(a), —R^(b)—OC(O)—N(R^(a))₂, —R^(b)—N(R^(a))₂, —R^(b)—C(O)R^(a), —R^(b)—C(O)OR^(a), —R^(b)—C(O)N(R^(a))₂, —R^(b)—O—R^(c)—C(O)N(R^(a))₂, —R^(b)—N(R^(a))C(O)OR^(a), —R^(b)—N(R^(a))C(O)R^(a), —R^(b)—N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)OR^(a) (where t is 1 or 2) and —R^(b)—S(O)_(t)N(R^(a))₂ (where t is 1 or 2), where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, cycloalkyl, cycloalkylalkyl, aryl (optionally substituted with one or more halo groups), aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl, each R^(b) is independently a direct bond or a straight or branched alkylene or alkenylene chain, and R^(c) is a straight or branched alkylene or alkenylene chain, and where each of the above substituents is unsubstituted unless otherwise indicated.

“Aralkyl” refers to a radical of the formula —R^(c)-aryl where R^(c) is an alkylene chain as defined above, for example, methylene, ethylene, and the like. The alkylene chain part of the aralkyl radical is optionally substituted as described above for an alkylene chain. The aryl part of the aralkyl radical is optionally substituted as described above for an aryl group.

“Aralkenyl” refers to a radical of the formula —R^(d)-aryl where R^(d) is an alkenylene chain as defined above. The aryl part of the aralkenyl radical is optionally substituted as described above for an aryl group. The alkenylene chain part of the aralkenyl radical is optionally substituted as defined above for an alkenylene group.

“Aralkynyl” refers to a radical of the formula —R^(e)-aryl, where R^(e) is an alkynylene chain as defined above. The aryl part of the aralkynyl radical is optionally substituted as described above for an aryl group. The alkynylene chain part of the aralkynyl radical is optionally substituted as defined above for an alkynylene chain.

“Aralkoxy” refers to a radical bonded through an oxygen atom of the formula —O—R^(c)-aryl where R^(c) is an alkylene chain as defined above, for example, methylene, ethylene, and the like. The alkylene chain part of the aralkyl radical is optionally substituted as described above for an alkylene chain. The aryl part of the aralkyl radical is optionally substituted as described above for an aryl group.

“Carbocyclyl” refers to a stable non-aromatic monocyclic or polycyclic hydrocarbon radical consisting solely of carbon and hydrogen atoms, which may include fused or bridged ring systems, having from three to fifteen carbon atoms. In certain embodiments, a carbocyclyl comprises three to ten carbon atoms. In other embodiments, a carbocyclyl comprises five to seven carbon atoms. The carbocyclyl is attached to the rest of the molecule by a single bond. Carbocyclyl may be saturated, (i.e., containing single C—C bonds only) or unsaturated (i.e., containing one or more double bonds or triple bonds.) A fully saturated carbocyclyl radical is also referred to as “cycloalkyl.” Examples of monocyclic cycloalkyls include, e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. An unsaturated carbocyclyl is also referred to as “cycloalkenyl.” Examples of monocyclic cycloalkenyls include, e.g., cyclopentenyl, cyclohexenyl, cycloheptenyl, and cyclooctenyl. Polycyclic carbocyclyl radicals include, for example, adamantyl, norbornyl (i.e., bicyclo[2.2.1]heptanyl), norbornenyl, decalinyl, 7,7-dimethyl-bicyclo[2.2.1]heptanyl, and the like. Unless otherwise stated specifically in the specification, the term “carbocyclyl” is meant to include carbocyclyl radicals that are optionally substituted by one or more substituents independently selected from alkyl, alkenyl, alkynyl, halo, fluoroalkyl, oxo, thioxo, cyano, nitro, optionally substituted aryl, optionally substituted aralkyl, optionally substituted aralkenyl, optionally substituted aralkynyl, optionally substituted carbocyclyl, optionally substituted carbocyclylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyl, —R^(b)—OR^(a), —R^(b)—OC(O)—R^(a), —R^(b)—OC(O)—OR^(a), —R^(b)—OC(O)—N(R^(a))₂, —R^(b)—N(R^(a))₂, —R^(b)—C(O)R^(a), —R^(b)—C(O)OR^(a), —R^(b)—C(O)N(R^(a))₂, —R^(b)—O—R^(c)—C(O)N(R^(a))₂, —R^(b)—N(R^(a))C(O)OR^(a), —R^(b)—N(R^(a))C(O)R^(a), —R^(b)—N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)OR^(a) (where t is 1 or 2) and —R^(b)—S(O)_(t)N(R^(a))₂ (where t is 1 or 2), where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl, each R^(b) is independently a direct bond or a straight or branched alkylene or alkenylene chain, and R^(c) is a straight or branched alkylene or alkenylene chain, and where each of the above substituents is unsubstituted unless otherwise indicated.

“Carbocyclylalkyl” refers to a radical of the formula R^(c)-carbocyclyl where R^(c) is an alkylene chain as defined above. The alkylene chain and the carbocyclyl radical is optionally substituted as defined above.

“Carbocyclylalkoxy” refers to a radical bonded through an oxygen atom of the formula —O—R^(c)-carbocyclyl where R^(c) is an alkylene chain as defined above. The alkylene chain and the carbocyclyl radical is optionally substituted as defined above.

“Halo” or “halogen” refers to bromo, chloro, fluoro or iodo substituents.

“Fluoroalkyl” refers to an alkyl radical, as defined above, that is substituted by one or more fluoro radicals, as defined above, for example, trifluoromethyl, difluoromethyl, fluoromethyl, 2,2,2-trifluoroethyl, 1-fluoromethyl-2-fluoroethyl, and the like. The alkyl part of the fluoroalkyl radical may be optionally substituted as defined above for an alkyl group.

“Heterocyclyl” refers to a stable 3- to 18-membered non-aromatic ring radical that comprises two to twelve carbon atoms and from one to six heteroatoms selected from nitrogen, oxygen and sulfur. Unless stated otherwise specifically in the specification, the heterocyclyl radical is a monocyclic, bicyclic, tricyclic or tetracyclic ring system, which may include fused or bridged ring systems. The heteroatoms in the heterocyclyl radical may be optionally oxidized. One or more nitrogen atoms, if present, are optionally quaternized. The heterocyclyl radical is partially or fully saturated. The heterocyclyl may be attached to the rest of the molecule through any atom of the ring(s). Examples of such heterocyclyl radicals include, but are not limited to, dioxolanyl, thienyl[1,3]dithianyl, decahydroisoquinolyl, imidazolinyl, imidazolidinyl, isothiazolidinyl, isoxazolidinyl, morpholinyl, octahydroindolyl, octahydroisoindolyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, oxazolidinyl, piperidinyl, piperazinyl, 4-piperidonyl, pyrrolidinyl, pyrazolidinyl, quinuclidinyl, thiazolidinyl, tetrahydrofuryl, trithianyl, tetrahydropyranyl, thiomorpholinyl, thiamorpholinyl, 1-oxo-thiomorpholinyl, and 1,1-dioxo-thiomorpholinyl. Unless stated otherwise specifically in the specification, the term “heterocyclyl” is meant to include heterocyclyl radicals as defined above that are optionally substituted by one or more substituents selected from alkyl, alkenyl, alkynyl, halo, fluoroalkyl, oxo, thioxo, cyano, nitro, optionally substituted aryl, optionally substituted aralkyl, optionally substituted aralkenyl, optionally substituted aralkynyl, optionally substituted carbocyclyl, optionally substituted carbocyclylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyl, —R^(b)—OR^(a), —R^(b)—OC(O)—R^(a), —R^(b)—OC(O)—OR^(a), —R^(b)—OC(O)—N(R^(a))₂, —R^(b)—N(R^(a))₂, —R^(b)—C(O)R^(a), —R^(b)—C(O)OR^(a), —R^(b)—C(O)N(R^(a))₂, —R^(b)—O—R^(c)—C(O)N(R^(a))₂, —R^(b)—N(R^(a))C(O)OR^(a), —R^(b)—N(R^(a))C(O)R^(a), —R^(b)—N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)OR^(a) (where t is 1 or 2) and —R^(b)—S(O)_(t)N(R^(a))₂ (where t is 1 or 2), where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl, each R^(b) is independently a direct bond or a straight or branched alkylene or alkenylene chain, and R^(c) is a straight or branched alkylene or alkenylene chain, and where each of the above substituents is unsubstituted unless otherwise indicated.

“N-heterocyclyl” or “N-attached heterocyclyl” refers to a heterocyclyl radical as defined above containing at least one nitrogen and where the point of attachment of the heterocyclyl radical to the rest of the molecule is through a nitrogen atom in the heterocyclyl radical. An N-heterocyclyl radical is optionally substituted as described above for heterocyclyl radicals. Examples of such N-heterocyclyl radicals include, but are not limited to, 1-morpholinyl, 1-piperidinyl, 1-piperazinyl, 1-pyrrolidinyl, pyrazolidinyl, imidazolinyl, and imidazolidinyl.

“C-heterocyclyl” or “C-attached heterocyclyl” refers to a heterocyclyl radical as defined above containing at least one heteroatom and where the point of attachment of the heterocyclyl radical to the rest of the molecule is through a carbon atom in the heterocyclyl radical. A C-heterocyclyl radical is optionally substituted as described above for heterocyclyl radicals. Examples of such C-heterocyclyl radicals include, but are not limited to, 2-morpholinyl, 2- or 3- or 4-piperidinyl, 2-piperazinyl, 2- or 3-pyrrolidinyl, and the like.

“Heterocyclylalkyl” refers to a radical of the formula —R^(c)-heterocyclyl where R^(c) is an alkylene chain as defined above. If the heterocyclyl is a nitrogen-containing heterocyclyl, the heterocyclyl is optionally attached to the alkyl radical at the nitrogen atom. The alkylene chain of the heterocyclylalkyl radical is optionally substituted as defined above for an alkylene chain. The heterocyclyl part of the heterocyclylalkyl radical is optionally substituted as defined above for a heterocyclyl group.

“Heterocyclylalkoxy” refers to a radical bonded through an oxygen atom of the formula —O—R^(c)-heterocyclyl where R^(c) is an alkylene chain as defined above. If the heterocyclyl is a nitrogen-containing heterocyclyl, the heterocyclyl is optionally attached to the alkyl radical at the nitrogen atom. The alkylene chain of the heterocyclylalkoxy radical is optionally substituted as defined above for an alkylene chain. The heterocyclyl part of the heterocyclylalkoxy radical is optionally substituted as defined above for a heterocyclyl group.

“Heteroaryl” refers to a radical derived from a 3- to 18-membered aromatic ring radical that comprises two to seventeen carbon atoms and from one to six heteroatoms selected from nitrogen, oxygen and sulfur. As used herein, the heteroaryl radical may be a monocyclic, bicyclic, tricyclic or tetracyclic ring system, wherein at least one of the rings in the ring system is fully unsaturated, i.e., it contains a cyclic, delocalized (4n+2) π-electron system in accordance with the Hückel theory. Heteroaryl includes fused or bridged ring systems. The heteroatom(s) in the heteroaryl radical is optionally oxidized. One or more nitrogen atoms, if present, are optionally quaternized. The heteroaryl is attached to the rest of the molecule through any atom of the ring(s). Examples of heteroaryls include, but are not limited to, azepinyl, acridinyl, benzimidazolyl, benzindolyl, 1,3-benzodioxolyl, benzofuranyl, benzooxazolyl, benzo[d]thiazolyl, benzothiadiazolyl, benzo[b][1,4]dioxepinyl, benzo[b][1,4]oxazinyl, 1,4-benzodioxanyl, benzonaphthofuranyl, benzoxazolyl, benzodioxolyl, benzodioxinyl, benzopyranyl, benzopyranonyl, benzofuranyl, benzofuranonyl, benzothienyl (benzothiophenyl), benzothieno[3,2-d]pyrimidinyl, benzotriazolyl, benzo[4,6]imidazo[1,2-a]pyridinyl, carbazolyl, cinnolinyl, cyclopenta[d]pyrimidinyl, 6,7-dihydro-5H-cyclopenta[4,5]thieno[2,3-d]pyrimidinyl, 5,6-dihydrobenzo[h]quinazolinyl, 5,6-dihydrobenzo[h]cinnolinyl, 6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-c]pyridazinyl, dibenzofuranyl, dibenzothiophenyl, furanyl, furanonyl, furo[3,2-c]pyridinyl, 5,6,7,8,9,10-hexahydrocycloocta[d]pyrimidinyl, 5,6,7,8,9,10-hexahydrocycloocta[d]pyridazinyl, 5,6,7,8,9,10-hexahydrocycloocta[d]pyridinyl, isothiazolyl, imidazolyl, indazolyl, indolyl, indazolyl, isoindolyl, indolinyl, isoindolinyl, isoquinolyl, indolizinyl, isoxazolyl, 5,8-methano-5,6,7,8-tetrahydroquinazolinyl, naphthyridinyl, 1,6-naphthyridinonyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl, oxiranyl, 5,6,6a,7,8,9,10,10a-octahydrobenzo[h]quinazolinyl, 1-phenyl-1H-pyrrolyl, phenazinyl, phenothiazinyl, phenoxazinyl, phthalazinyl, pteridinyl, purinyl, pyrrolyl, pyrazolyl, pyrazolo[3,4-d]pyrimidinyl, pyridinyl, pyrido[3,2-d]pyrimidinyl, pyrido-[3,4-d]pyrimidinyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrrolyl, quinazolinyl, quinoxalinyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl, 5,6,7,8-tetrahydroquinazolinyl, 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidinyl, 6,7,8,9-tetrahydro-5H-cyclohepta[4,5]thieno[2,3-d]pyrimidinyl, 5,6,7,8-tetrahydropyrido[4,5-c]pyridazinyl, thiazolyl, thiadiazolyl, triazolyl, tetrazolyl, triazinyl, thieno[2,3-d]pyrimidinyl, thieno[3,2-d]pyrimidinyl, thieno[2,3-c]pridinyl, and thiophenyl (i.e. thienyl). Unless stated otherwise specifically in the specification, the term “heteroaryl” is meant to include heteroaryl radicals as defined above which are optionally substituted by one or more substituents selected from alkyl, alkenyl, alkynyl, halo, fluoroalkyl, haloalkenyl, haloalkynyl, oxo, thioxo, cyano, nitro, optionally substituted aryl, optionally substituted aralkyl, optionally substituted aralkenyl, optionally substituted aralkynyl, optionally substituted carbocyclyl, optionally substituted carbocyclylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl, optionally substituted heteroarylalkyl, —R^(b)—OR^(a), —R^(b)—OC(O)—R^(a), —R^(b)—OC(O)—OR^(a), —R^(b)—OC(O)—N(R^(a))₂, —R^(b)—N(R^(a))₂, —R^(b)—C(O)R^(a), —R^(b)—C(O)OR^(a), —R^(b)—C(O)N(R^(a))₂, —R^(b)—O—R^(c)—C(O)N(R^(a))₂, —R^(b)—N(R^(a))C(O)OR^(a), —R^(b)—N(R^(a))C(O)R^(a), —R^(b)—N(R^(a))S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)R^(a) (where t is 1 or 2), —R^(b)—S(O)_(t)OR^(a) (where t is 1 or 2) and —R^(b)—S(O)_(t)N(R^(a))₂ (where t is 1 or 2), where each R^(a) is independently hydrogen, alkyl, fluoroalkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heterocyclyl, heterocyclylalkyl, heteroaryl or heteroarylalkyl, each R^(b) is independently a direct bond or a straight or branched alkylene or alkenylene chain, and R^(c) is a straight or branched alkylene or alkenylene chain, and where each of the above substituents is unsubstituted unless otherwise indicated.

“N-heteroaryl” refers to a heteroaryl radical as defined above containing at least one nitrogen and where the point of attachment of the heteroaryl radical to the rest of the molecule is through a nitrogen atom in the heteroaryl radical. An N-heteroaryl radical is optionally substituted as described above for heteroaryl radicals.

“C-heteroaryl” refers to a heteroaryl radical as defined above and where the point of attachment of the heteroaryl radical to the rest of the molecule is through a carbon atom in the heteroaryl radical. A C-heteroaryl radical is optionally substituted as described above for heteroaryl radicals.

“Heteroarylalkyl” refers to a radical of the formula R^(c)-heteroaryl, where R^(c) is an alkylene chain as defined above. If the heteroaryl is a nitrogen-containing heteroaryl, the heteroaryl is optionally attached to the alkyl radical at the nitrogen atom. The alkylene chain of the heteroarylalkyl radical is optionally substituted as defined above for an alkylene chain. The heteroaryl part of the heteroarylalkyl radical is optionally substituted as defined above for a heteroaryl group.

“Heteroarylalkoxy” refers to a radical bonded through an oxygen atom of the formula —O—R^(c)-heteroaryl, where R^(c) is an alkylene chain as defined above. If the heteroaryl is a nitrogen-containing heteroaryl, the heteroaryl is optionally attached to the alkyl radical at the nitrogen atom. The alkylene chain of the heteroarylalkoxy radical is optionally substituted as defined above for an alkylene chain. The heteroaryl part of the heteroarylalkoxy radical is optionally substituted as defined above for a heteroaryl group.

As used herein, “carboxylic acid bioisostere” refers to a functional group or moiety that exhibits similar physical, biological and/or chemical properties as a carboxylic acid moiety. Examples of carboxylic acid bioisosteres include, but are not limited to,

and the like.

The compounds disclosed herein may contain one or more asymmetric centers and may thus give rise to enantiomers, diastereomers, and other stereoisomeric forms that may be defined, in terms of absolute stereochemistry, as (R)- or (S)-. Unless stated otherwise, it is intended that all stereoisomeric forms of the compounds disclosed herein are contemplated by this disclosure. When the compounds described herein contain alkene double bonds, and unless specified otherwise, it is intended that this disclosure includes both E and Z geometric isomers (e.g., cis or trans). Likewise, all possible isomers, as well as their racemic and optically pure forms, and all tautomeric forms are also intended to be included. The term “geometric isomer” refers to E or Z geometric isomers (e.g., cis or trans) of an alkene double bond. The term “positional isomer” refers to structural isomers around a central ring, such as ortho-, meta-, and para-isomers around a benzene ring.

A “tautomer” refers to a molecule wherein a proton shift from one atom of a molecule to another atom of the same molecule is possible. The compounds presented herein may, in certain embodiments, exist as tautomers. In circumstances where tautomerization is possible, a chemical equilibrium of the tautomers will exist. The exact ratio of the tautomers depends on several factors, including physical state, temperature, solvent, and pH. Some examples of tautomeric equilibrium include:

“Optional” or “optionally” means that a subsequently described event or circumstance may or may not occur and that the description includes instances when the event or circumstance occurs and instances in which it does not. For example, “optionally substituted aryl” means that the aryl radical may or may not be substituted and that the description includes both substituted aryl radicals and aryl radicals having no substitution.

“Pharmaceutically acceptable salt” includes both acid and base addition salts. A pharmaceutically acceptable salt of any one of the substituted pyrrolopyridine derivative compounds described herein is intended to encompass any and all pharmaceutically suitable salt forms. Preferred pharmaceutically acceptable salts of the compounds described herein are pharmaceutically acceptable acid addition salts and pharmaceutically acceptable base addition salts.

“Pharmaceutically acceptable acid addition salt” refers to those salts which retain the biological effectiveness and properties of the free bases, which are not biologically or otherwise undesirable, and which are formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, hydroiodic acid, hydrofluoric acid, phosphorous acid, and the like. Also included are salts that are formed with organic acids such as aliphatic mono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, alkanedioic acids, aromatic acids, aliphatic and. aromatic sulfonic acids, etc. and include, for example, acetic acid, trifluoroacetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, and the like. Exemplary salts thus include sulfates, pyrosulfates, bisulfates, sulfites, bisulfates, nitrates, phosphates, monohydrogenphosphates, dihydrogenphosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, trifluoroacetates, propionates, caprylates, isobutyrates, oxalates, malonates, succinate suberates, sebacates, fumarates, maleates, mandelates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, phthalates, benzenesulfonates, toluenesulfonates, phenylacetates, citrates, lactates, malates, tartrates, methanesulfonates, and the like. Also contemplated are salts of amino acids, such as arginates, gluconates, and galacturonates (see, for example, Berge S. M. et al., “Pharmaceutical Salts,” Journal of Pharmaceutical Science, 66:1-19 (1997), which is hereby incorporated by reference in its entirety). Acid addition salts of basic compounds may be prepared by contacting the free base forms with a sufficient amount of the desired acid to produce the salt according to methods and techniques with which a skilled artisan is familiar

“Pharmaceutically acceptable base addition salt” refers to those salts that retain the biological effectiveness and properties of the free acids, which are not biologically or otherwise undesirable. These salts are prepared from addition of an inorganic base or an organic base to the free acid. Pharmaceutically acceptable base addition salts may be formed with metals or amines, such as alkali and alkaline earth metals or organic amines. Salts derived from inorganic bases include, but are not limited to, sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum salts and the like. Salts derived from organic bases include, but are not limited to, salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, for example, isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, diethanolamine, 2-dimethylaminoethanol, 2-diethylaminoethanol, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, N,N-dibenzylethylenediamine, chloroprocaine, hydrabamine, choline, betaine, ethylenediamine, ethylenedianiline, N-methylglucamine, glucosamine, methylglucamine, theobromine, purines, piperazine, piperidine, N-ethylpiperidine, polyamine resins and the like. See Berge et al., supra.

As used herein, “treatment” or “treating,” or “palliating” or “ameliorating” are used interchangeably herein. These terms refers to an approach for obtaining beneficial or desired results including but not limited to therapeutic benefit and/or a prophylactic benefit. By “therapeutic benefit” is meant eradication or amelioration of the underlying disorder being treated. Also, a therapeutic benefit is achieved with the eradication or amelioration of one or more of the physiological symptoms associated with the underlying disorder such that an improvement is observed in the patient, notwithstanding that the patient may still be afflicted with the underlying disorder. For prophylactic benefit, the compositions may be administered to a patient at risk of developing a particular disease, or to a patient reporting one or more of the physiological symptoms of a disease, even though a diagnosis of this disease may not have been made.

“Prodrug” is meant to indicate a compound that may be converted under physiological conditions or by solvolysis to a biologically active compound described herein. Thus, the term “prodrug” refers to a precursor of a biologically active compound that is pharmaceutically acceptable. A prodrug may be inactive when administered to a subject, but is converted in vivo to an active compound, for example, by hydrolysis. The prodrug compound often offers advantages of solubility, tissue compatibility or delayed release in a mammalian organism (see, e.g., Bundgard, H., Design of Prodrugs (1985), pp. 7-9, 21-24 (Elsevier, Amsterdam).

A discussion of prodrugs is provided in Higuchi, T., et al., “Pro-drugs as Novel Delivery Systems,” A.C.S. Symposium Series, Vol. 14, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987, both of which are incorporated in full by reference herein.

The term “prodrug” is also meant to include any covalently bonded carriers, which release the active compound in vivo when such prodrug is administered to a mammalian subject. Prodrugs of an active compound, as described herein, may be prepared by modifying functional groups present in the active compound in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent active compound. Prodrugs include compounds wherein a hydroxy, amino or mercapto group is bonded to any group that, when the prodrug of the active compound is administered to a mammalian subject, cleaves to form a free hydroxy, free amino or free mercapto group, respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol or amine functional groups in the active compounds and the like. In some embodiments, the substituted pyrrolopyridine derivative compounds described herein are obtained by the in vivo oxidation of an aldehyde prodrug, or aldehyde-equivalent prodrug precursor. As illustrated below, the aldehyde-equivalent prodrug precursor is transformed in vivo into an aldehyde prodrug. In vivo oxidation of the aldehyde prodrug affords the substituted pyrrolopyridine derivative compounds described herein. The aldehyde-equivalent prodrug precursor is an aldehyde derivate such as imine, hydrazone, oxime, or the like.

Substituted Pyrrolopyridine Derivative Compounds

Substituted pyrrolopyridine derivative compounds are described herein that inhibit a histone demethylase enzyme. These compounds, and compositions comprising these compounds, are useful for the treatment of cancer and neoplastic disease. The compounds described herein may, therefore, be useful for treating prostate cancer, breast cancer, bladder cancer, lung cancer and/or melanoma and the like.

One embodiment provides a compound having the structure of Formula (I),

or a pharmaceutically acceptable salt thereof,

-   wherein, -   R¹ is hydrogen or alkyl; -   R² is hydrogen, halogen or alkyl; -   G is

-   n is 0, 1, or 2; -   R³ is alkyl, carbocyclyl, carbocyclylalkyl, heterocyclyl, or     heterocyclylalkyl; -   R⁴ is halogen, alkyl, alkoxy, carbocyclyl, heterocyclyl, aryl,     heteroaryl, or X—R⁵;     -   wherein:     -   X is —(C₁-C₆)alkylene-, —O—, —S—, or —NR¹—; and     -   R⁵ is carbocyclyl, heterocyclyl, aryl, or heteroaryl.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R¹ is hydrogen. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R¹ is alkyl. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R¹ is methyl.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R² is hydrogen.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein the compound of Formula (I) is of Formula (Ia):

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein the compound of Formula (I) is of Formula (Ib):

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R³ is alkyl. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R³ is methyl. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R³ is alkyl substituted with at least one halogen.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R³ is carbocyclylalkyl or heterocyclylalkyl. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R³ is selected from a group consisting of:

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is halogen. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is chloro or fluoro. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is alkyl substituted with at least one halogen. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is —CF₃.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is alkoxy. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is methoxy. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is alkoxy substituted with at least one halogen. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is —OCF₃.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is carbocyclyl.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is heterocyclyl. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein the heterocyclyl is selected from a group consisting of:

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁴ is X—R⁵. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein X is —O—. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein X is —S—. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein X is —NR¹—; and R¹ is methyl.

Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁵ is aryl. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein the aryl is phenyl optionally substituted with halogen, —CN, alkyl, alkynyl, alkoxy, or carbocycle. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein R⁵ is heteroaryl. Another embodiment provides the compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein the heteroaryl is pyridinyl optionally substituted with halogen, —CN, alkyl, alkynyl, alkoxy, or carbocycle.

One embodiment provides a compound having the structure of Formula (II),

or a pharmaceutically acceptable salt thereof,

-   wherein, -   R¹ is hydrogen or alkyl; -   R² is hydrogen, halogen or alkyl; -   G is

-   n is 0, 1, or 2; -   R⁴ is halogen, alkyl, alkoxy, carbocyclyl, heterocyclyl, aryl,     heteroaryl, or X—R⁵;     -   wherein:     -   X is —(C₁-C₆)alkylene-, —O—, —S—, or —NR¹—; and     -   R⁵ is carbocyclyl, heterocyclyl, aryl, or heteroaryl.

Another embodiment provides the compound of Formula (II), or a pharmaceutically acceptable salt thereof, wherein G is

Another embodiment provides the compound of Formula (II), or a pharmaceutically acceptable salt thereof, wherein G is

Another embodiment provides the compound of Formula (II), or a pharmaceutically acceptable salt thereof, wherein G is

Another embodiment provides the compound of Formula (II), or a pharmaceutically acceptable salt thereof, wherein G is

Another embodiment provides the compound of Formula (II), or a pharmaceutically acceptable salt thereof, wherein R⁴ is aryl. Another embodiment provides the compound of Formula (II), or a pharmaceutically acceptable salt thereof, wherein R⁴ is X—R⁵. Another embodiment provides the compound of Formula (II), or a pharmaceutically acceptable salt thereof, wherein R⁴ is X—R⁵; X is NR¹—; and R⁵ is aryl.

In some embodiments, the compound of Formula (I) as disclosed herein has the structure provided in Table 1.

TABLE 1 Chemical Synthesis Example Structure Name  1

2-(6-methoxy-2-methyl-2H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid  2

2-(5-methoxy-2-methyl-2H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid  3

2-(6-chloro-2-methyl-2H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid  4

2-[2-methyl-5-(trifluoromethyl)-2H-indazol-3-yl]- 1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid  5

2-[2-methyl-5-(trifluoromethoxy)-2H-indazol-3- yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid  6

2-(5-cyclopropyl-2-methyl-2H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid  7

2-(5-chloro-2-methyl-2H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid  8

2-(6-chloro-2-ethyl-2H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid  9

2-[6-chloro-2-(cyclopropylmethyl)-2H-indazol-3- yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid 10

2-{5-chloro-2-[2-(pyrrolidin-1-yl)ethyl]-2H- indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7- carboxylic acid 11

2-{2-methyl-6-[methyl(phenyl)amino]-2H- indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7- carboxylic acid 12

2-{2-methyl-7-[methyl(phenyl)amino]-2H- indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7- carboxylic acid 13

2-(1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2- b]pyridine-7-carboxylic acid 14

2-(5-fluoro-1-methyl-1H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid 15

2-(6-chloro-1-methyl-1H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid 16

2-(6-fluoro-1-methyl-1H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid 17

2-(6-chloro-1-ethyl-1H-indazol-3-yl)-1H- pyrrolo[3,2-b]pyridine-7-carboxylic acid 18

2-[6-chloro-1-(cyclopropylmethyl)-1H-indazol-3- yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid 19

2-[6-chloro-1-(2,2,2-trifluoroethyl)-1H-indazol-3- yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid 20

2-{5-chloro-1-[2-(pyrrolidin-1-yl)ethyl]-1H- indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7- carboxylic acid 21

2-{5-fluoro-1-[2-(morpholin-4-yl)ethyl]-1H- indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7- carboxylic acid

In additional embodiments, the compound of Formula (I) is selected from a compound provided in Table 2.

TABLE 2

Preparation of the Substituted Pyrrolopyridine Derivative Compounds

The compounds used in the reactions described herein are made according to organic synthesis techniques known to those skilled in this art, starting from commercially available chemicals and/or from compounds described in the chemical literature. “Commercially available chemicals” are obtained from standard commercial sources including Acros Organics (Pittsburgh, Pa.), Aldrich Chemical (Milwaukee, Wis., including Sigma Chemical and Fluka), Apin Chemicals Ltd. (Milton Park, UK), Avocado Research (Lancashire, U.K.), BDH Inc. (Toronto, Canada), Bionet (Cornwall, U.K.), Chemservice Inc. (West Chester, Pa.), Crescent Chemical Co. (Hauppauge, N.Y.), Eastman Organic Chemicals, Eastman Kodak Company (Rochester, N.Y.), Fisher Scientific Co. (Pittsburgh, Pa.), Fisons Chemicals (Leicestershire, UK), Frontier Scientific (Logan, Utah), ICN Biomedicals, Inc. (Costa Mesa, Calif.), Key Organics (Cornwall, U.K.), Lancaster Synthesis (Windham, N.H.), Maybridge Chemical Co. Ltd. (Cornwall, U.K.), Parish Chemical Co. (Orem, Utah), Pfaltz & Bauer, Inc. (Waterbury, Conn.), Polyorganix (Houston, Tex.), Pierce Chemical Co. (Rockford, Ill.), Riedel de Haen AG (Hanover, Germany), Spectrum Quality Product, Inc. (New Brunswick, N.J.), TCI America (Portland, Oreg.), Trans World Chemicals, Inc. (Rockville, Md.), and Wako Chemicals USA, Inc. (Richmond, Va.).

Methods known to one of ordinary skill in the art are identified through various reference books and databases. Suitable reference books and treatise that detail the synthesis of reactants useful in the preparation of compounds described herein, or provide references to articles that describe the preparation, include for example, “Synthetic Organic Chemistry”, John Wiley & Sons, Inc., New York; S. R. Sandler et al., “Organic Functional Group Preparations,” 2nd Ed., Academic Press, New York, 1983; H. O. House, “Modern Synthetic Reactions”, 2nd Ed., W. A. Benjamin, Inc. Menlo Park, Calif. 1972; T. L. Gilchrist, “Heterocyclic Chemistry”, 2nd Ed., John Wiley & Sons, New York, 1992; J. March, “Advanced Organic Chemistry: Reactions, Mechanisms and Structure”, 4th Ed., Wiley-Interscience, New York, 1992. Additional suitable reference books and treatise that detail the synthesis of reactants useful in the preparation of compounds described herein, or provide references to articles that describe the preparation, include for example, Fuhrhop, J. and Penzlin G. “Organic Synthesis: Concepts, Methods, Starting Materials”, Second, Revised and Enlarged Edition (1994) John Wiley & Sons ISBN: 3-527-29074-5; Hoffman, R. V. “Organic Chemistry, An Intermediate Text” (1996) Oxford University Press, ISBN 0-19-509618-5; Larock, R. C. “Comprehensive Organic Transformations: A Guide to Functional Group Preparations” 2nd Edition (1999) Wiley-VCH, ISBN: 0-471-19031-4; March, J. “Advanced Organic Chemistry: Reactions, Mechanisms, and Structure” 4th Edition (1992) John Wiley & Sons, ISBN: 0-471-60180-2; Otera, J. (editor) “Modern Carbonyl Chemistry” (2000) Wiley-VCH, ISBN: 3-527-29871-1; Patai, S. “Patai's 1992 Guide to the Chemistry of Functional Groups” (1992) Interscience ISBN: 0-471-93022-9; Solomons, T. W. G. “Organic Chemistry” 7th Edition (2000) John Wiley & Sons, ISBN: 0-471-19095-0; Stowell, J. C., “Intermediate Organic Chemistry” 2nd Edition (1993) Wiley-Interscience, ISBN: 0-471-57456-2; “Industrial Organic Chemicals: Starting Materials and Intermediates: An Ullmann's Encyclopedia” (1999) John Wiley & Sons, ISBN: 3-527-29645-X, in 8 volumes; “Organic Reactions” (1942-2000) John Wiley & Sons, in over 55 volumes; and “Chemistry of Functional Groups” John Wiley & Sons, in 73 volumes.

Specific and analogous reactants may also be identified through the indices of known chemicals prepared by the Chemical Abstract Service of the American Chemical Society, which are available in most public and university libraries, as well as through on-line databases (the American Chemical Society, Washington, D.C., may be contacted for more details). Chemicals that are known but not commercially available in catalogs may be prepared by custom chemical synthesis houses, where many of the standard chemical supply houses (e.g., those listed above) provide custom synthesis services. A reference for the preparation and selection of pharmaceutical salts of the substituted pyrrolopyridine derivative compounds described herein is P. H. Stahl & C. G. Wermuth “Handbook of Pharmaceutical Salts”, Verlag Helvetica Chimica Acta, Zurich, 2002.

The substituted pyrrolopyridine derivative compounds are prepared by the general synthetic routes described below in Schemes 1-3.

Referring to Scheme 1, the substituted indazole A is selectively alkylated with R₁—X to give compound B (See Cheung, J. Org. Chem. 2003, 4093). Compound B is iodinated in the presence of base to give compound C. Alternatively, compound A is iodinated in the presence of base to give compound D. Compound D is alkylated with R¹—X to give a mixture of compound E (major) and compound C (minor).

Referring to Scheme 2, Compound F is converted to the acetylene compound G using TMS-acetylene under Sonigashira conditions, followed by TMS deprotection with TBAF. Compound G and the halo-indazole C are converted to compound H under Sonigashira coupling conditions. Compound H is heated in the presence of base and copper in order to cyclize to the compound J. Compound J is hydrolyzed under basic conditions to give compound K.

Referring to Scheme 3, Compound F is converted to the acetylene compound G using TMS-acetylene under Sonigashira conditions, followed by TMS deprotection with TBAF. Compound G and the halo-indazole E are converted to compound L under Sonigashira coupling conditions. Compound L is heated in the presence of base and copper in order to cyclize to the compound M. Compound M is hydrolyzed under basic conditions to give compound N.

In each of the above reaction procedures or schemes, the various substituents may be selected from among the various substituents otherwise taught herein.

Pharmaceutical Compositions

In certain embodiments, a substituted pyrrolopyridine derivative compound as described herein is administered as a pure chemical. In other embodiments, the substituted pyrrolopyridine derivative compound as described herein is combined with a pharmaceutically suitable or acceptable carrier (also referred to herein as a pharmaceutically suitable (or acceptable) excipient, physiologically suitable (or acceptable) excipient, or physiologically suitable (or acceptable) carrier) selected on the basis of a chosen route of administration and standard pharmaceutical practice as described, for example, in Remington: The Science and Practice of Pharmacy (Gennaro, 21^(st) Ed. Mack Pub. Co., Easton, Pa. (2005)), the disclosure of which is hereby incorporated herein by reference, in its entirety.

Accordingly, provided herein is a pharmaceutical composition comprising at least one substituted pyrrolopyridine derivative compound as described herein, or a stereoisomer, pharmaceutically acceptable salt, hydrate, solvate, or N-oxide thereof, together with one or more pharmaceutically acceptable carriers. The carrier(s) (or excipient(s)) is acceptable or suitable if the carrier is compatible with the other ingredients of the composition and not deleterious to the recipient (i.e., the subject) of the composition.

One embodiment provides a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a compound of Formula (I), or a pharmaceutically acceptable salt thereof.

In certain embodiments, the substituted pyrrolopyridine derivative compound as described herein is substantially pure, in that it contains less than about 5%, or less than about 1%, or less than about 0.1%, of other organic small molecules, such as contaminating intermediates or by-products that are created, for example, in one or more of the steps of a synthesis method.

Suitable oral dosage forms include, for example, tablets, pills, sachets, or capsules of hard or soft gelatin, methylcellulose or of another suitable material easily dissolved in the digestive tract. Suitable nontoxic solid carriers can be used which include, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like. (See, e.g., Remington: The Science and Practice of Pharmacy (Gennaro, 21^(st) Ed. Mack Pub. Co., Easton, Pa. (2005)).

The dose of the composition comprising at least one substituted pyrrolopyridine derivative compound as described herein may differ, depending upon the patient's (e.g., human) condition, that is, stage of the disease, general health status, age, and other factors that a person skilled in the medical art will use to determine dose.

Pharmaceutical compositions may be administered in a manner appropriate to the disease to be treated (or prevented) as determined by persons skilled in the medical arts. An appropriate dose and a suitable duration and frequency of administration will be determined by such factors as the condition of the patient, the type and severity of the patient's disease, the particular form of the active ingredient, and the method of administration. In general, an appropriate dose and treatment regimen provides the composition(s) in an amount sufficient to provide therapeutic and/or prophylactic benefit (e.g., an improved clinical outcome, such as more frequent complete or partial remissions, or longer disease-free and/or overall survival, or a lessening of symptom severity. Optimal doses may generally be determined using experimental models and/or clinical trials. The optimal dose may depend upon the body mass, weight, or blood volume of the patient.

Oral doses can typically range from about 1.0 mg to about 1000 mg, one to four times, or more, per day.

Histone Demethylase

Chromatin is the complex of DNA and protein that makes up chromosomes. Histones are the major protein component of chromatin, acting as spools around which DNA winds. Changes in chromatin structure are affected by covalent modifications of histone proteins and by non-histone binding proteins. Several classes of enzymes are known which can covalently modify histones at various sites.

Proteins can be post-translationally modified by methylation on amino groups of lysines and guanidino groups of arginines or carboxymethylated on aspartate, glutamate, or on the C-terminus of the protein. Post-translational protein methylation has been implicated in a variety of cellular processes such as RNA processing, receptor mediated signaling, and cellular differentiation. Post-translational protein methylation is widely known to occur on histones, such reactions known to be catalyzed by histone methyltransferases, which transfer methyl groups from S-adenyosyl methionine (SAM) to histones. Histone methylation is known to participate in a diverse range of biological processes including heterochromatin formation, X-chromosome inactivation, and transcriptional regulation (Lachner et al., (2003) J. Cell Sci. 116:2117-2124; Margueron et al., (2005) Curr. Opin. Genet. Dev. 15:163-176).

Unlike acetylation, which generally correlates with transcriptional activation, whether histone methylation leads to transcription activation or repression depends on the particular site of methylation and the degree of methylation (e.g., whether a particular histone lysine residue is mono-, di-, or tri-methylated). However, generally, methylation on H3K9, H3K27 and H4K20 is linked to gene silencing, while methylation on H3K4, H3K36, and H3K79 is generally associated with active gene expression. In addition, tri- and di-methylation of H3K4 generally marks the transcriptional start sites of actively transcribed genes, whereas mono-methylation of H3K4 is associated with enhancer sequences.

A “demethylase” or “protein demethylase,” as referred to herein, refers to an enzyme that removes at least one methyl group from an amino acid side chain. Some demethylases act on histones, e.g., act as a histone H3 or H4 demethylase. For example, an H3 demethylase may demethylate one or more of H3K4, H3K9, H3K27, H3K36 and/or H3K79. Alternately, an H4 demethylase may demethylate histone H4K20. Demethylases are known which can demethylate either a mono-, di- and/or a tri-methylated substrate. Further, histone demethylases can act on a methylated core histone substrate, a mononucleosome substrate, a dinucleosome substrate and/or an oligonucleosome substrate, peptide substrate and/or chromatin (e.g., in a cell-based assay).

The first lysine demethylase discovered was lysine specific demethylase 1 (LSD1/KDM1), which demethylates both mono- and di-methylated H3K4 or H3K9, using flavin as a cofactor. A second class of Jumonji C (JmjC) domain containing histone demethylases were predicted, and confirmed when a H3K36 demethylase was found using a formaldehyde release assay, which was named JmjC domain containing histone demethylase 1 (JHDM1/KDM2A).

More JmjC domain-containing proteins were subsequently identified and they can be phylogenetically clustered into seven subfamilies. JHDM1, JHDM2, JHDM3, JMJD2, JARID, PHF2/PHF8, UTX/UTY, and JmjC domain only.

JMJD2 Family

The JMJD2 family of proteins are a family of histone-demethylases known to demethylate tri- and di-methylated H3-K9, and were the first identified histone tri-methyl demethylases. In particular, ectopic expression of JMJD2 family members was found to dramatically decrease levels of tri- and di-methylated H3-K9, while increasing levels of mono-methylated H3-K9, which delocalized Heterochromatin Protein 1 (HP1) and reduced overall levels of heterochromatin in vivo. Members of the JMJD2 subfamily of jumonji proteins include JMJD2C and its homologues JMJD2A, JMJD2B, JMJD2D and JMJD2E. Common structural features found in the JMJD2 subfamily of Jumonji proteins include the JmjN, JmjC, PHD and Tdr sequences.

JMJD2C, also known as GASC1 and KDM4C, is known to demethylate tri-methylated H3K9 and H3K36. Histone demethylation by JMJD2C occurs via a hydroxylation reaction dependent on iron and α-ketoglutarate, wherein oxidative decarboxylation of α-ketoglutarate by JMJD2C produces carbon dioxide, succinate, and ferryl and ferryl subsequently hydroxylates a methyl group of lysine H3K9, releasing formaldehyde. JMJD2C is known to modulate regulation of adipogenesis by the nuclear receptor PPARγ and is known to be involved in regulation of self-renewal in embryonic stem cells.

JARID Family

As used herein, a “JARID protein” includes proteins in the JARID1 subfamily (e.g., JARID1A, JARID1B, JARID1C and JARID1D proteins) and the JARID2 subfamily, as well as homologues thereof. A further description and listing of JARID proteins can be found in Klose et al. (2006) Nature Reviews/Genetics 7:715-727. The JARID1 family contains several conserved domains: JmjN, ARID, JmjC, PHD and a C5HC2 zing finger.

JARID1A, also called KDM5A or RBP2, was initially found as a binding partner of retinoblastoma (Rb) protein. JARID1A was subsequently found to function as a demethylase of tri- and di-methylated H3K4, and has been found to promote cell growth, while inhibiting senescence and differentiation. For instance, abrogation of JARID1A from mouse cells inhibits cell growth, induces senescence and differentiation, and causes loss of pluripotency of embryonic stem cells in vitro. JARID1A has been found to be overexpressed in gastric cancer and the loss of JARID1A has been found to reduce tumorigenesis in a mouse cancer model. Additionally, studies have demonstrated that loss of the retinoblastome binding protein 2 (RBP2) histone demethylase suppresses tumorigenesis in mice lacking Rb1 or Men1 (Lin et al. Proc. Natl. Acad. Sci. USA, Aug. 16, 2011, 108(33), 13379-86; doi: 10.1073/pnas.1110104108) and lead to the conclusion that RBP2-inhibitory drugs would have anti-cancer activity.

JARID1B, also referred to as KDM5B and PLU1, was originally found in experiments to discover genes regulated by the HER2 tyrosine kinase. JARID1B has consistently been found to be expressed in breast cancer cell lines, although restriction of JARID1B has been found in normal adult tissues, with the exception of the testis. In addition, 90% of invasive ductal carcinomas have been found to express JARID1B. In addition, JARID1B has been found to be up-regulated in prostate cancers, while having more limited expression in benign prostate, and has also been found to be up-regulated in bladder cancer and lung cancer (both SCLC and NSCLC). JARID1B has also been found to repress tumor suppressor genes such as BRCA1, CAV1 and 14-3-3σ, and knockdown of JARID1B was found to increase the levels of tri-methylated H3K4 at these genes.

In an additional embodiment is a method for inhibiting a histone-demethylase enzyme comprising contacting a histone demethylase enzyme with a compound of Formula (I), or a pharmaceutically acceptable salt thereof.

In an additional embodiment is the method for inhibiting a histone-demethylase enzyme, wherein the histone-demethylase enzyme comprises a JmjC domain. In an additional embodiment is the method for inhibiting a histone-demethylase enzyme, wherein the histone-demethylase enzyme is JMJD2C.

Methods of Treatment

Disclosed herein are methods of modulating demethylation in a cell or in a subject, either generally or with respect to one or more specific target genes. Demethylation can be modulated to control a variety of cellular functions, including without limitation: differentiation; proliferation; apoptosis; tumorigenesis, leukemogenesis or other oncogenic transformation events; hair loss; or sexual differentiation. For example, in particular embodiments, the invention provides a method of treating a disease regulated by histone methylation and/or demethylation in a subject in need thereof by modulating the activity of a demethylase comprising a JmjC domain (e.g., a histone demethylase such as a JMJD2C protein(s)).

In an additional embodiment is a method for treating cancer in subject in need thereof comprising administering to the subject a composition comprising a compound of Formula (I), or a pharmaceutically acceptable salt thereof.

In a further embodiment is the method for treating cancer in a subject wherein the cancer is selected from prostate cancer, breast cancer, bladder cancer, lung cancer or melanoma.

In an additional embodiment is a method for inhibiting the growth of a tumor comprising administering a composition comprising a compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein the tumor is characterized by a loss of retinoblastoma gene (RBI) function.

In an additional embodiment is a method for inhibiting the growth of a tumor comprising administering a composition comprising a compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein the tumor is characterized by a loss of multiple endocrine neoplasia type 1 gene (Men1) function.

Other embodiments and uses will be apparent to one skilled in the art in light of the present disclosures. The following examples are provided merely as illustrative of various embodiments and shall not be construed to limit the invention in any way.

EXAMPLES

I. Chemical Synthesis

Unless otherwise noted, reagents and solvents were used as received from commercial suppliers. Anhydrous solvents and oven-dried glassware were used for synthetic transformations sensitive to moisture and/or oxygen. Yields were not optimized Reaction times are approximate and were not optimized. Column chromatography and thin layer chromatography (TLC) were performed on silica gel unless otherwise noted. Spectra are given in ppm (δ) and coupling constants, J are reported in Hertz. For proton spectra the solvent peak was used as the reference peak.

Preparation 1a: Methyl 3-amino-2-ethynylpyridine-4-carboxylate

A mixture of methyl 3-amino-2-chloropyridine-4-carboxylate (1.86 g, 10 mmol), TMS-acetylene (1.18 g, 12 mmol), Pd(PPh₃)₂Cl₂ (350 mg, 0.50 mmol), CuI (48 mg, 0.25 mmol), TEA (5.05 g, 50 mmol) and acetonitrile (50 mL) was purged with nitrogen and stirred at 40° C. overnight. Solvent was removed and the residue was dissolved in dichloromethane and filtered. The filtrate was concentrated and re-dissolved in THF (10 mL). The mixture was cooled 0° C. and TBAF (1M, 0.35 mL) was added dropwise, and the reaction stirred 30 min. The mixture was concentrated and purified by silica gel chromatography (PE/EA=10/1 to 5/1) to afford 1.1 g, (62%) of the title compound as a yellow solid. [M+H] Calc'd for C₉H₈N₂O₂, 177. Found, 177.

Preparation 1b: 3-Iodo-6-methoxy-2-methyl-2H-indazole

To a mixture of 6-methoxy-2-methyl-2H-indazole (900 mg, 5.55 mmol) in DMF (30 mL) was added KOH (1.25 g, 22.2 mmol) followed by portion-wise addition of I₂ (3.0 g, 22 mmol). The reaction was allowed to stir at rt for 16 h. Upon completion, the reaction was quenched with NaHCO₃ (sat′d, 20 mL) and the content was extracted with ethyl acetate (30 mL). The organics were washed with brine, dried over Na₂SO₄, and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (PE/EA=2/1) to afford 1.19 g (74%) of the title compound as a yellow solid. [M+H] Calc'd for C₉H₉IN₂O, 289. Found, 289.

Preparation 1c: Methyl 3-amino-2-[2-(6-methoxy-2-methyl-2H-indazol-3-yl)ethynyl]pyridine-4-carboxylate

A round-bottom flask charged with 3-iodo-6-methoxy-2-methyl-2H-indazole (432 mg, 1.50 mmol) in acetonitrile (10 mL), methyl 3-amino-2-ethynylpyridine-4-carboxylate (264 mg, 1.50 mmol), Pd(PPh₃)₂Cl₂ (53 mg, 0.075 mmol), CuI (8 mg, 0.04 mmol), and TEA (2 ml) was purged with nitrogen for 2 min and allowed to stir at 40° C. for 16 h. The reaction was filtered and the filtrate was concentrated in vacuo. The residue was purified by silica gel chromatography (PE/EA=1/2) to afford 154 mg (30%) of the title compound as a brown solid. [M+H] Calc'd for C₁₈H₁₆N₄O₃, 337. Found, 337.

Preparation 1d: Methyl 2-(6-methoxy-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

A round-bottom flask charged with methyl 3-amino-2-[2-(6-methoxy-2-methyl-2H-indazol-3-yl)ethynyl]pyridine-4-carboxylate (154 mg, 0.458 mmol) in DMF (10 mL), CaCO₃ (46 mg, 0.46 mmol), and CuI (22 mg, 0.11 mmol) was purged with nitrogen and stirred for 12 h at 120° C. The reaction concentrated in vacuo, and the residue was taken up in dichloromethane and filtered. The filtrate was concentrated in vacuo and purified by prep-HPLC to afford 20 mg (13%) of the title compound as a yellow solid. [M+] Calc'd for C₁₈H₁₆N₄O₃, 337. Found, 337.

Example 1 2-(6-Methoxy-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

A round-bottom flask charged with methyl 2-(6-methoxy-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate (20 mg, 0.059 mmol) in THF (1 mL), LiOH H₂O (5 mg, 0.12 mmol) and water (1 mL) was allowed to stir at rt for 3 h. The pH was adjusted to 6˜7 with HCl (1N), and the precipitate filtered. The solid was washed with dichloromethane and dried to afford 13 mg (68%) of the title compound as an orange solid. ¹H NMR (300 MHz, DMSO-d₆): δ 4.11 (3H, s), 4.25 (3H, s), 7.23 (1H, J=9.3 Hz, d), 7.50-7.53 (2H, m), 7.83 (1H, J=9.0 Hz, d), 8.45-8.49 (2H, m), 12.79 (1H, s). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.804 min. [M+H] Calc'd for C₁₇H₁₄N₄O₃, 323. Found, 323.

Preparation 2a: 5-Methoxy-2-methyl-2H-indazole

To a solution of 5-methoxy-indazole (1.0 g, 6.7 mmol) in ethyl acetate (10 ml) was added BF₄O(CH₃)₃ (1.3 g, 8.9 mmol). The solution was stirred at rt for 3 h. Sat. NaHCO₃ aq. (10 ml) was added and extracted with ethyl acetate (20 ml). Organics were dried over Na₂SO₄, concentrated, and purified by flash chromatography on silica gel (PE/EA=2/1) to afford 0.64 g (59%) of the title compound as a yellow solid. [M+H] Calc'd for C₉H₁₀N₂O, 163. Found, 163.

Preparation 2b: 3-Iodo-5-methoxy-2-methyl-2H-indazole

The title compound was prepared in 70% yield from 5-methoxy-2-methyl-2H-indazole according to the procedure for Preparation 1b. [M+H] Calc'd for C₉H₉IN₂O, 289. Found, 289.

Example 2 2-(5-Methoxy-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in <10% overall yield starting from Preparation 2b according to the procedure sequence for the preparation of Example 1 (Preparation 1c, Preparation 1d, Example 1). ¹H NMR (300 MHz, DMSO-d₆): δ 3.78 (3H, s), 4.22 (3H, s), 6.97-7.01 (2H, m), 7.12 (1H, s), 7.59-7.63 (2H, m), 8.55-8.57 (1H, m), 11.62 (1H, s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% TFA): purity is >95%, Rt=2.853 min. [M+H] Calc'd for C₁₇H₁₄N₄O₃, 323. Found, 323.

Preparation 3a: Methyl 3-amino-2-[2-(6-chloro-2-methyl-2H-indazol-3-yl)ethynyl]pyridine-4-carboxylate

A mixture of methyl 3-amino-2-ethynylpyridine-4-carboxylate (176 mg, 1 mmol), 6-chloro-3-iodo-2-methyl-2H-indazole (1 mmol), Pd(ACN)₂Cl₂ (7 mg, 0.025 mmol), xphos (24 mg, 0.05 mmol), K₂CO₃ (552 mg, 4 mmol) and acetonitrile (10 mL) was purged with nitrogen and stirred at 80° C. overnight. The reaction was filtered, and the filtrate was concentrated and purified by silica gel chromatography (PE/EA=5/1˜2/1) to afford 300 mg (88%) of the title compound as a yellow solid. [M+H] Calc'd for C₁₇H₁₃ClN₄O₂, 341. Found, 341.

Preparation 3b: Methyl 2-(6-chloro-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

A mixture of Preparation 3a (170 mg, 0.5 mmol), CaCO₃ (100 mg, 1 mmol), CuI (24 mg, 0.125 mmol) and DMF (10 mL) was purged with nitrogen and stirred for 1 h at 120° C. The solvent was removed, and the residue was dissolved in dichloromethane and filtered. The filtrate was concentrated and purified by prep-HPLC to give 65 mg (38%) of the title compound. ¹H NMR (400 MHz, DMSO-d₆): δ 3.99 (3H, s), 4.27 (3H, s), 7.15-7.21 (2H, m), 7.70-7.82 (3H, m), 8.62 (1H, d, J=4.8 Hz), 11.86 (1H, br s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.930 min [M+H] Calc'd for C₁₇H₁₃ClN₄O₂, 341. Found, 341.

Example 3 2-(6-Chloro-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

A mixture of Preparation 3b (0.16 mmol) and NaOH (14 mg, 0.35 mmol) in methanol (1 mL) and water (1 mL) was heated at 60° C. for 15 min. The solution was cooled to rt, and the pH was adjusted to 3˜4 with aq. 1N HCl. The resulting precipitate was collected by filtration, washing with DCM, and dried under vacuum to give 20 mg (60%) of the title compound. ¹H NMR (400 MHz, DMSO-d₆): δ 4.27 (3H, s), 7.15-7.19 (2H, m), 7.68-7.80 (3H, m), 8.60 (1H, s), 11.82 (1H, br). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.482 min. [M+H] Calc'd for C₁₆H₁₁ClN₄O₂, 327. Found, 327.

Preparation 4a: Methyl 3-amino-2-{2-[2-methyl-5-(trifluoromethyl)-2H-indazol-3-yl]ethynyl}pyridine-4-carboxylate

The title compound was prepared in 85% yield from 3-iodo-2-methyl-5-(trifluoromethyl)-2H-indazole according to the procedure for Preparation 3a. [M+H] Calc'd for C₁₈H₁₃F₃N₄O₂, 375. Found, 375.

Preparation 4b: Methyl 2-[2-methyl-5-(trifluoromethyl)-2H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 43% yield from Preparation 4a according to the procedure for Preparation 3b. ¹H NMR (300 MHz, DMSO-d₆): δ 4.01 (3H, s), 4.32 (3H, s), 7.30 (1H, s), 7.55-7.59 (1H, m), 7.71-7.73 (1H, m), 7.93 (1H, d, J=9.3 Hz), 8.10 (1H, s), 8.62-8.64 (1H, m), 11.97 (1H, s). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.766 min. [M+H] Calc'd for C₁₈H₁₃F₃N₄O₂, 375. Found, 375.

Example 4 2-[2-Methyl-5-(trifluoromethyl)-2H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 70% yield from Preparation 4b according to the procedure for Example 3. ¹H NMR (400 MHz, DMSO-d₆): δ 4.31 (3H, s), 7.26 (1H, s), 7.56 (1H, d, J=9.2 Hz), 7.68 (1H, d, J=4.8 Hz), 7.91 (1H, d, J=9.2 Hz), 8.09 (1H, s), 8.59-8.63 (1H, m), 11.91 (1H, s), 13.81 (1H, br). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.371 min. [M+H] Calc'd for C₁₇H₁₁F₃N₄O₂, 361. Found, 361.

Preparation 5a: Methyl 3-amino-2-{2-[2-methyl-5-(trifluoromethoxy)-2H-indazol-3-yl]ethynyl}pyridine-4-carboxylate

The title compound was prepared in 79% yield from 3-iodo-2-methyl-5-(trifluoromethoxy)-2H-indazole according to the procedure for Preparation 3a. [M+H] Calc'd for C₁₈H₁₃F₃N₄O₃, 391. Found, 391.

Preparation 5b: Methyl 2-[2-methyl-5-(trifluoromethoxy)-2H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 66% yield from Preparation 5a according to the procedure for Preparation 3b. ¹H NMR (400 MHz, DMSO-d₆): δ 3.99 (3H, s), 4.29 (3H, s), 7.22 (1H, s), 7.32-7.34 (1H, m), 7.63 (1H, s), 7.71 (1H, d, J=4.4 Hz), 7.86 (1H, d, J=9.2 Hz), 8.62 (1H, d, J=4.8 Hz), 11.86 (1H, s). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.857 min. [M+H] Calc'd for C₁₈H₁₃F₃N₄O₃, 391. Found, 391.

Example 5 2-[2-Methyl-5-(trifluoromethoxy)-2H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 88% yield from Preparation 5b according to the procedure for Example 3. ¹H NMR (400 MHz, DMSO-d₆): δ 4.29 (3H, s), 7.19 (1H, s), 7.31-7.33 (1H, m), 7.63-7.68 (2H, m), 7.84 (1H, d, J=9.2 Hz), 8.60 (1H, d, J=4.8 Hz), 11.82 (1H, s), 13.83 (1H, br s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.610 min. [M+H] Calc'd for C₁₇H₁₁F₃N₄O₃, 377. Found, 377.

Preparation 6a: Methyl 3-amino-2-[2-(5-cyclopropyl-2-methyl-2H-indazol-3-yl)ethynyl]pyridine-4-carboxylate

The title compound was prepared in 81% yield from 5-cyclopropyl-3-iodo-2-methyl-2H-indazole according to the procedure for Preparation 3a. [M+H] Calc'd for C₂₀H₁₈N₄O₂, 347. Found, 347.

Preparation 6b: Methyl 2-(5-cyclopropyl-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 40% yield from Preparation 6a according to the procedure for Preparation 3b. ¹H NMR (400 MHz, CDCl₃): δ 0.76-0.78 (2H, m), 0.98-1.02 (2H, m), 2.02-2.04 (1H, m), 4.08 (3H, s), 4.37 (3H, s), 7.06-7.13 (2H, m), 7.12 (1H, s), 7.52 (1H, s), 7.66-7.71 (1H, m), 8.66 (1H, d, J=4.8 Hz), 9.94 (1H, s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.972 min. [M+H] Calc'd for C₂₀H₁₈N₄O₂, 347. Found, 347.

Example 6 2-(5-Cyclopropyl-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 85% yield from Preparation 6b according to the procedure for Example 3. ¹H NMR (400 MHz, DMSO-d₆): δ 0.69-0.71 (2H, m), 0.91-0.94 (2H, m), 2.01-2.04 (1H, m), 4.24 (3H, s), 7.04-7.12 (2H, m), 7.41 (1H, s), 7.57-7.65 (2H, m), 8.57 (1H, d, J=5.2 Hz), 11.64 (1H, s), 13.76 (1H, br s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.612 min. [M+H] Calc'd for C₁₉H₁₆N₄O₂, 333. Found, 333.

Example 7 2-(5-Chloro-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in <10% overall yield starting from 6-chloro-3-iodo-2-methyl-2H-indazole according to the procedure sequence for the preparation of Example 1 (Preparation 1c, Preparation 1d, Example 1). ¹H NMR (400 MHz, DMSO-d₆): δ 4.36 (3H, s), 6.66 (1H, s), 7.06 (1H, d, J=4.6 Hz), 7.18 (1H, dd, J=8.9, 2.1 Hz), 7.57 (1H, d, J=8.9 Hz), 7.89 (1H, s), 7.92 (1H, d, J=4.6 Hz). [M+H] Calc'd for C₁₆H₁₁ClN₄O₂, 327. Found, 327.

Preparation 8a: 6-Chloro-3-iodo-1H-indazole

To a solution of 6-chloro-indazole (3.0 g, 20 mmol) and KOH (4.2 g, 74 mmol) in DMF (80 mL) was added I₂ (10 g, 40 mmol) at 0° C. The mixture was stirred at rt for 3 h. The reaction was quenched with sat. Na₂S₂O₃ (30 mL) and extracted with EA (50 mL). Organics were dried over Na₂SO₄, filtered, and the filtrate was concentrated and purified by silica gel chromatography (PE/EA=5/1) to afford 3.9 g (71%) of the title compound as a red solid. [M+H] Calc'd for C₇H₄ClIN₂, 279. Found, 279.

Preparation 8b: 6-Chloro-1-ethyl-3-iodo-1H-indazole Preparation 8c: 6-Chloro-2-ethyl-3-iodo-2H-indazole

A mixture of 6-chloro-3-iodo-1H-indazole (1.11 g, 4 mmol), K₂CO₃ (1.11 g, 8 mmol), and iodoethane (1.6 mL, 20 mmol) in acetonitrile (15 mL) was stirred at 80° C. overnight. The reaction was filtered and the filtrate was concentrated and purified by silica gel chromatography (PE/EA=1/1) to afford the two products as yellow solids.

6-chloro-1-ethyl-3-iodo-1H-indazole (866 mg, 60%): [M+H] Calc'd for C₉H₈ClIN₂, 307. Found, 307.

6-chloro-2-ethyl-3-iodo-2H-indazole (260 mg, 18%): [M+H] Calc'd for C₉H₈ClIN₂, 307. Found, 307.

Preparation 8d: methyl 3-amino-2-[2-(6-chloro-2-ethyl-2H-indazol-3-yl)ethynyl]pyridine-4-carboxylate

The title compound was prepared in 80% yield from Preparation 8c according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₁₈H₁₅ClN₄O₂, 355. Found, 355.

Preparation 8e: Methyl 2-(6-chloro-2-ethyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 11% yield from Preparation 8d according to the general procedure outline for Preparation 1d. ¹H NMR (400 MHz, DMSO-d₆): δ 1.57 (3H, J=7.2 Hz, t), 4.08 (3H, s), 4.64-4.70 (2H, m), 7.10 (1H, s), 7.17-7.19 (1H, m), 7.72-7.74 (2H, m), 7.84 (1H, d, J=5.2 Hz), 8.60 (1H, d, J=4.8 Hz). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=4.144 min [M+H] Calc'd for C₁₈H₁₅ClN₄O₂, 355. Found, 355.

Example 8 2-(6-Chloro-2-ethyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 64% yield from Preparation 8e according to the general procedure outline for Example 1. ¹H NMR (400 MHz, DMSO-d₆): δ 1.45 (3H, J=7.2 Hz, t), 4.56-4.58 (2H, m), 7.13-7.15 (2H, m), 7.68-7.72 (2H, m), 7.82 (1H, s), 8.62 (1H, J=4.8 Hz, d), 11.93 (1H, br s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.872 min. [M+H] Calc'd for C₁₇H₁₃ClN₄O₂, 341. Found, 341.

Preparation 9a: 6-Chloro-1-(cyclopropylmethyl)-3-iodo-1H-indazole Preparation 9b: 6-Chloro-2-(cyclopropylmethyl)-3-iodo-2H-indazole

The title compounds were prepared from (iodomethyl)cyclopropane and 6-chloro-3-iodo-1H-indazole according to the procedure for Preparation 8b and 8c.

6-chloro-1-(cyclopropylmethyl)-3-iodo-1H-indazole: (61%). [M+H] Calc'd for C₁₁H₁₀ClIN₂, 333. Found, 333.

6-chloro-2-(cyclopropylmethyl)-3-iodo-2H-indazole: (19%). [M+H] Calc'd for C₁₁H₁₀ClIN₂, 333. Found, 333.

Preparation 9c: Methyl 3-amino-2-{2-[6-chloro-2-(cyclopropylmethyl)-2H-indazol-3-yl]ethynyl}pyridine-4-carboxylate

The title compound was prepared in 82% yield from Preparation 9b according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₂₀H₁₇ClN₄O₂, 381. Found, 381.

Preparation 9d: Methyl 2-[6-chloro-2-(cyclopropylmethyl)-2H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 31% yield from Preparation 9c according to the general procedure outline for Preparation 1d. ¹H NMR (400 MHz, DMSO-d₆): δ 0.30-0.32 (2H, m), 0.54-0.56 (2H, m), 1.34-1.37 (1H, m), 4.08 (3H, s), 4.51 (2H, J=7.2 Hz, d), 7.11 (1H, s), 7.17 (1H, J=8.0 Hz, d), 7.71-7.73 (2H, m), 7.84-7.85 (1H, m), 8.60 (1H, s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=4.238 min. [M+H] Calc'd for C₂₀H₁₇ClN₄O₂, 381. Found, 381.

Example 9 2-[6-Chloro-2-(cyclopropylmethyl)-2H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 73% yield from Preparation 9d according to the general procedure outline for Example 1. ¹H NMR (300 MHz, DMSO-d₆): δ 0.24-0.28 (2H, m), 0.43-0.47 (2H, m), 1.24-1.29 (1H, m), 4.45 (2H, J=7.2 Hz, d), 7.15-7.19 (2H, m), 7.69-7.74 (2H, m), 7.86 (1H, s), 8.64 (1H, J=5.2 Hz), 12.03 (1H, br). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.741 min. [M+H] Calc'd for C₁₉H₁₅ClN₄O₂, 367. Found, 367.

Preparation 10a: 5-Chloro-3-iodo-1-[2-(pyrrolidin-1-yl)ethyl]-1H-indazole Preparation 10b: 5-Chloro-3-iodo-2-[2-(pyrrolidin-1-yl)ethyl]-2H-indazole

The title compounds were prepared from 1-(2-chloroethyl)pyrrolidine hydrochloride and 5-chloro-3-iodo-1H-indazole according to the procedure for Preparation 8b and 8c.

5-chloro-3-iodo-1-[2-(pyrrolidin-1-yl)ethyl]-1H-indazole (39%). [M+H] Calc'd for C₁₃H₁₅ClIN₃, 376. Found, 376.

5-chloro-3-iodo-2-[2-(pyrrolidin-1-yl)ethyl]-2H-indazole (21%). [M+H] Calc'd for C₁₃H₁₅ClIN₃, 376. Found, 376.

Preparation 10c: Methyl 3-amino-2-(2-{5-chloro-2-[2-(pyrrolidin-1-yl)ethyl]-2H-indazol-3-yl}ethynyl)pyridine-4-carboxylate

The title compound was prepared in 69% yield from Preparation 10b according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₂₂H₂₂ClN₅O₂, 424. Found, 424.

Preparation 10d: Methyl 2-{5-chloro-2-[2-(pyrrolidin-1-yl)ethyl]-2H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 35% yield from Preparation 10c according to the general procedure outline for Preparation 1d. Calc'd for C₂₂H₂₂ClN₅O₂, 424. Found, 424.

Example 10 2-{5-Chloro-2-[2-(pyrrolidin-1-yl)ethyl]-2H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 69% yield from Preparation 10d according to the general procedure outline for Example 1. ¹H NMR (400 MHz, D₂O): δ 1.75 (4H, br s), 2.71 (4H, br s), 3.56 (2H, t, J=6.4 Hz), 4.82 (2H, t, J=6.4 Hz), 7.24 (1H, s), 7.37 (1H, dd, J=9.0, 2.0 Hz), 7.67 (1H, d, J=5.1 Hz), 7.75-7.81 (2H, m), 8.60 (1H, d, J=4.8 Hz). [M+H] Calc'd for C₂₁H₂₀ClN₅O₂, 410. Found, 410.

Preparation 11a: 6-Bromo-3-chloro-2-methyl-2H-indazole

To a solution of 6-bromo-2-methyl-2H-indazole (1.0 g, 4.7 mmol) in AcOH (10 mL) was added SO₂Cl₂ (0.58 mL, 7.1 mmol). The solution was stirred at rt for 4 h. 2M aq. NaOH (60 mL) was added, and the reaction was extracted with EA (100 mL). Organics were dried over Na₂SO₄, concentrated, and purified by flash chromatography on silica gel (PE/EA=5/1) to afford 1.1 g (96%) of the title compound as a yellow solid. [M+H] Calc'd for C₈H₆BrClN₂, 245. Found, 245.

Preparation 11b: 3-Chloro-N,2-dimethyl-N-phenyl-2H-indazol-6-amine

A mixture of 6-bromo-3-chloro-2-methyl-2H-indazole (1.0 g, 4.10 mmol), N-methyl-aniline (627 mg, 4.10 mmol), Pd₂dba₃ (73 mg, 0.08 mmol), xantphos (138 mg, 0.24 mmol), and t-BuOK (642 mg, 5.74 mmol) in toluene (50 mL) was purged with nitrogen and stirred at 120° C. overnight. The reaction was filtered and concentrated. Purification by silica gel chromatography (PE/EA=10/1) gave 222 mg (20%) of the title compound as a yellow solid. [M+H] Calc'd for C₁₅H₁₄ClN₃, 272. Found, 272.

Preparation 11c: Methyl 3-amino-2-(2-{2-methyl-6-[methyl(phenyl)amino]-2H-indazol-3-yl}ethynyl)pyridine-4-carboxylate

A mixture of Preparation 11b (408 mg, 1.50 mmol), methyl 3-amino-2-ethynylpyridine-4-carboxylate (264 mg, 1.50 mmol), Pd(ACN)₂Cl₂ (12 mg, 0.037 mmol), xphos (36 mg, 0.075 mmol), and K₂CO₃ (828 mg, 6.00 mmol) in acetonitrile (10 mL) was purged with nitrogen and stirred at 110° C. overnight. The reaction was filtered, and the filtrate was concentrated and purified by silica gel chromatography (PE/EA=1/2) to afford 308 mg (50%) of the title compound as a yellow solid. [M+H] Calc'd for C₂₄H₂₁N₅O₂, 412. Found, 412.

Preparation 11d: Methyl 2-{2-methyl-6-[methyl(phenyl)amino]-2H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 15% yield from Preparation 11c according to the procedure for Preparation 3b. [M+H] Calc'd for C₂₄H₂₁N₅O₂, 412. Found, 412.

Example 11 2-{2-Methyl-6-[methyl(phenyl)amino]-2H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 87% yield from Preparation 11d according to the general procedure outline for Example 1. ¹H NMR (300 MHz, DMSO-d₆): δ 3.34 (3H, s), 4.21 (3H, s), 6.80-6.84 (1H, m), 6.90-6.95 (1H, m), 6.99-7.02 (2H, m), 7.07 (1H, s), 7.15 (1H, s), 7.24-7.29 (2H, m), 7.56-7.59 (2H, m), 8.50 (1H, J=4.8 Hz, d), 11.52 (1H, s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% TFA): purity is >95%, Rt=3.449 min. [M+H] Calc'd for C₂₃H₁₉N₅O₂, 398. Found, 398.

Preparation 12a: 7-Bromo-3-chloro-2-methyl-2H-indazole

The title compound was prepared in 87% yield from 7-bromo-2-methyl-2H-indazole according to the general procedure for Preparation 11a. [M+H] Calc'd for C₈H₆BrClN₂, 245. Found, 245.

Preparation 12b: 3-Chloro-N,2-dimethyl-N-phenyl-2H-indazol-7-amine

The title compound was prepared in 29% yield from Preparation 12a according to the general procedure for Preparation 11b. [M+H] Calc'd for C₁₅H₁₄ClN₃, 272. Found, 272.

Preparation 12c: Methyl 3-amino-2-(2-{2-methyl-7-[methyl(phenyl)amino]-2H-indazol-3-yl}ethynyl)pyridine-4-carboxylate

The title compound was prepared in 37% yield from Preparation 12b according to the general procedure for Preparation 11c. [M+H] Calc'd for C₂₄H_(2t)N₅O₂, 412. Found, 412.

Preparation 12d: Methyl 2-{2-methyl-7-[methyl(phenyl)amino]-2H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 20% yield from Preparation 12c according to the procedure for Preparation 3b. [M+H] Calc'd for C₂₄H₂₁N₅O₂, 412. Found, 412.

Example 12 2-{2-Methyl-7-[methyl(phenyl)amino]-2H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 87% yield from Preparation 12d according to the general procedure outline for Example 1. ¹H NMR (300 MHz, DMSO-d₆): δ 3.46 (3H, s), 4.24 (3H, s), 6.77-6.84 (3H, m), 7.04-7.21 (5H, m), 7.54-7.59 (2H, m), 8.51 (1H, J=4.5 Hz, d), 11.56 (1H, s).

LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.531 min. [M+H] Calc'd for C₂₃H₁₉N₅O₂, 398. Found, 398.

Preparation 13a: Methyl 2-(1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

Methyl 3-amino-2-chloropyridine-4-carboxylate (186 mg, 1.0 mmol), 1-(1-methyl-1H-indazol-3-yl)ethanone (348 mg, 2.0 mmol), MgSO₄ (120 mg), and acetic acid (85 μL, 1.5 mmol) were combined in DMA (3 mL), and the reaction mixture was purged with nitrogen for 10 min. Pd(PtBu₃)₂ (50 mg, 0.1 mmol) and K₃PO₄ (276 mg, 1.3 mmol) were added. The reaction vessel was sealed and heated at 120° C. for 16 h. The reaction was concentrated and purified by prep-HPLC (20-65% ACN/water with 0.1% formic acid) to give 36 mg (12%) of the title compound. [M+H] Calc'd for C₁₇H₁₄N₄O₂, 307. Found, 307.

Example 13 2-(1-Methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 72% yield from Preparation 13a according to the procedure for Example 1. [M+H] Calc'd for C₁₆H₁₂N₄O₂, 293. Found, 293.

Example 14 2-(5-Fluoro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in <10% overall yield starting from 5-fluoro-3-iodo-1-methyl-1H-indazole according to the procedure sequence for the preparation of Example 1 (Preparation 1c, Preparation 1d, Example 1). ¹H NMR (400 MHz, DMSO-d₆): δ 4.19 (3H, s), 7.35-7.45 (3H, m), 7.80 (1H, dd, J=9.1, 4.2 Hz), 8.04 (1H, d, J=9.2 Hz), 8.25-8.32 (2H, m), 11.05 (1H, s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% TFA): purity is >95%, Rt=2.853 min. [M+H] Calc'd for C₁₆H₁₁FN₄O₂, 311. Found, 311.

Preparation 15a: 6-Chloro-3-iodo-1-methyl-1H-indazole Preparation 15b: 6-Chloro-3-iodo-2-methyl-2H-indazole

The title compounds were prepared from iodomethane and 6-chloro-3-iodo-1H-indazole according to the procedure for Preparation 8b and 8c.

6-chloro-3-iodo-1-methyl-1H-indazole: (61%). [M+H] Calc'd for C₈H₆ClIN₂, 293. Found, 293.

6-chloro-3-iodo-2-methyl-2H-indazole: (22%). [M+H] Calc'd for C₈H₆ClIN₂, 293. Found, 293.

Preparation 15c: Methyl 3-amino-2-[2-(6-chloro-1-methyl-1H-indazol-3-yl)ethynyl]pyridine-4-carboxylate

The title compound was prepared in 96% yield from Preparation 15a according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₁₇H₁₃ClN₄O₂, 341. Found, 341.

Preparation 15d: Methyl 2-(6-chloro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 6% yield from Preparation 15c according to the general procedure outline for Preparation 1d. ¹H NMR (400 MHz, MeOD-d₄): δ 4.20 (3H, s), 4.24 (3H, s), 7.40-7.46 (2H, m), 7.85 (1H, s), 8.03 (1H, J=5.6 Hz, d), 8.16 (1H, J=8.8 Hz, d), 8.64 (1H, J=5.6 Hz, d). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity >95%, Rt=4.388 min. [M+H] Calc'd for C₁₇H₁₃ClN₄O₂, 341. Found, 341.

Example 15 2-(6-Chloro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 67% yield from Preparation 16d according to the general procedure outline for Example 1. ¹H NMR (400 MHz, DMSO-d₆): δ 4.18 (3H, s), 7.31-7.34 (1H, m), 7.48-7.50 (1H, m), 7.61-7.63 (1H, m), 7.98-8.00 (1H, m), 8.31-8.33 (1H, m), 8.53-8.55 (1H, m), 10.49 (1H, br s). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.952 min. [M+H] Calc'd for C₁₆H₁₁ClN₄O₂, 327. Found, 327.

Preparation 16a: 6-Fluoro-3-iodo-1-methyl-1H-indazole Preparation 16b: 6-Fluoro-3-iodo-2-methyl-2H-indazole

The title compounds were prepared from iodomethane and 6-fluoro-3-iodo-1H-indazole according to the procedure for Preparation 8b and 8c.

6-fluoro-3-iodo-1-methyl-1H-indazole: (61%). [M+H] Calc'd for C₈H₆FIN₂, 277. Found, 277.

6-fluoro-3-iodo-2-methyl-2H-indazole: (20%). [M+H] Calc'd for C₈H₆FIN₂, 277. Found, 277.

Preparation 16c: Methyl 3-amino-2-[2-(6-fluoro-1-methyl-1H-indazol-3-yl)ethynyl]pyridine-4-carboxylate

The title compound was prepared in 90% yield from Preparation 16a according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₁₇H₁₃FN₄O₂, 325. Found, 325.

Preparation 16d: Methyl 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 8% yield from Preparation 16c according to the general procedure outline for Preparation 1d. ¹H NMR (400 MHz, DMSO-d₆): δ 4.03 (3H, s), 4.16 (3H, s), 7.18-7.21 (1H, m), 7.61-7.70 (2H, m), 8.29-8.33 (1H, m), 8.55-8.58 (1H, m), 10.75 (1H, s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=4.150 min. [M+H] Calc'd for C₁₇H₁₃FN₄O₂, 325. Found, 325.

Example 16 2-(6-Fluoro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 67% yield from Preparation 16d according to the general procedure outline for Example 1. ¹H NMR (400 MHz, DMSO-d₆): δ 4.15 (3H, s), 7.19-7.21 (1H, m), 7.50 (1H, s), 7.59 (1H, J=4.0 Hz, d), 7.68 (1H, J=10.4 Hz, d), 8.33-8.36 (1H, m), 8.53 (1H, J=4.8 Hz, d), 10.42 (1H, br s). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=2.809 min. [M+H] Calc'd for C₁₆H₁₁FN₄O₂, 311. Found, 311.

Preparation 17a: Methyl 3-amino-2-[2-(6-chloro-1-ethyl-1H-indazol-3-yl)ethynyl]pyridine-4-carboxylate

The title compound was prepared in 45% yield from Preparation 8b according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₁₈H₁₅ClN₄O₂, 355. Found, 355.

Preparation 17b: Methyl 2-(6-chloro-1-ethyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 13% yield from Preparation 17a according to the general procedure outline for Preparation 1d. ¹H NMR (400 MHz, MeOD-d₄): δ 1.62 (3H, J=7.2 Hz, t), 4.18 (3H, s), 4.61-4.63 (2H, m), 7.39-7.41 (2H, m), 7.85 (1H, s), 7.98 (1H, J=5.6 Hz, d), 8.12 (1H, J=4.8 Hz, d), 8.61 (1H, J=5.6 Hz, d). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=4.628 min. [M+H] Calc'd for C₁₈H₁₅ClN₄O₂, 355. Found, 355.

Example 17 2-(6-Chloro-1-ethyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 71% yield from Preparation 17b according to the general procedure outline for Example 1. ¹H NMR (400 MHz, DMSO-d₆): δ 1.48 (3H, J=6.8 Hz, t), 4.59-4.60 (2H, m), 7.34 (1H, J=8.4 Hz, d), 7.50 (1H, s), 7.66 (1H, J=4.4 Hz, d), 8.05 (1H, s), 8.31 (1H, J=8.8 Hz, d), 8.57 (1H, J=4.4 Hz, d), 10.66 (1H, br s). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.115 min. [M+H] Calc'd for C₁₇H₁₃ClN₄O₂, 341. Found, 341.

Preparation 18a: Methyl 3-amino-2-{2-[6-chloro-1-(cyclopropylmethyl)-1H-indazol-3-yl]ethynyl}pyridine-4-carboxylate

The title compound was prepared in 90% yield from Preparation 9a according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₂₀H₁₇ClN₄O₂, 381. Found, 381.

Preparation 18b: Methyl 2-[6-chloro-1-(cyclopropylmethyl)-1H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 16% yield from Preparation 18a according to the general procedure outline for Preparation 1d. ¹H NMR (400 MHz, MeOD-d₄): δ 0.52-0.56 (2H, m), 0.64-0.68 (2H, m), 1.46-1.48 (1H, m), 4.11 (3H, s), 4.40 (2H, J=7.2 Hz, d), 7.28 (1H, s), 7.31-7.33 (1H, m), 7.71-7.77 (2H, m), 8.12 (1H, J=8.4 Hz, d), 8.48 (1H, J=5.2 Hz, d). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=4.848 min. [M+H] Calc'd for C₂₀H₁₇ClN₄O₂, 381. Found, 381.

Example 18 2-[6-Chloro-1-(cyclopropylmethyl)-1H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 60% yield from Preparation 18b according to the general procedure outline for Example 1. ¹H NMR (300 MHz, DMSO-d₆): δ 0.47-0.54 (4H, m), 1.38-1.42 (1H, m), 4.46 (2H, J=6.8 Hz, d), 7.31-7.34 (1H, m), 7.50 (1H, s), 7.60 (1H, J=4.8 Hz, d), 8.08 (1H, s), 8.33 (1H, J=8.8 Hz, d), 8.54 (1H, J=4.8 Hz, d), 10.45 (1H, br s). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.209 min. [M+H] Calc'd for C₁₉H₁₅ClN₄O₂, 367. Found, 367.

Preparation 19a: 6-Chloro-3-iodo-1-(2,2,2-trifluoroethyl)-1H-indazole Preparation 19b: 6-Chloro-3-iodo-2-(2,2,2-trifluoroethyl)-2H-indazole

The title compounds were prepared from 1,1,1-trifluoro-2-iodoethane and 6-chloro-3-iodo-1H-indazole according to the procedure for Preparation 8b and 8c.

6-chloro-3-iodo-1-(2,2,2-trifluoroethyl)-1H-indazole: (60%). [M+H] Calc'd for C₉H₅ClF₃IN₂, 361. Found, 361.

6-chloro-3-iodo-2-(2,2,2-trifluoroethyl)-2H-indazole: (20%). [M+H] Calc'd for C₉H₅ClF₃IN₂, 361. Found, 361.

Preparation 19c: Methyl 3-amino-2-{2-[6-chloro-1-(2,2,2-trifluoroethyl)-1H-indazol-3-yl]ethynyl}pyridine-4-carboxylate

The title compound was prepared in 78% yield from Preparation 19a according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₁₈H₁₂ClF₃N₄O₂, 409. Found, 409.

Preparation 19d: Methyl 2-[6-chloro-1-(2,2,2-trifluoroethyl)-1H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 13% yield from Preparation 19c according to the general procedure outline for Preparation 1d. ¹H NMR (400 MHz, MeOD-d₄): δ 4.11 (3H, s), 5.34-5.41 (2H, m), 7.35 (s, 1H), 7.39-7.41 (1H, m), 7.74 (1H, J=5.2 Hz, d), 7.85 (1H, s), 8.17 (1H, J=8.8 Hz, d), 8.51 (1H, J=5.2 Hz, d). LCMS (mobile phase: 5%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=4.583 min. [M+H] Calc'd for C₁₈H₁₂ClF₃N₄O₂, 409. Found, 409.

Example 19 2-[6-Chloro-1-(2,2,2-trifluoroethyl)-1H-indazol-3-yl]-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 74% yield from Preparation 19d according to the general procedure outline for Example 1. ¹H NMR (300 MHz, DMSO-d₆): δ 5.64-5.67 (2H, m), 7.41-7.43 (1H, m), 7.59-7.64 (2H, m), 8.17 (1H, s), 8.39 (1H, J=8.4 Hz, d), 8.57 (1H, J=4.8 Hz, d), 10.46 (1H, br s). LCMS (mobile phase: 10%-95% Acetonitrile-Water-0.02% NH₄Ac): purity is >95%, Rt=3.231 min. [M+H] Calc'd for C₁₇H₁₀ClF₃N₄O₂, 395. Found, 395.

Preparation 20a: Methyl 3-amino-2-(2-{5-chloro-1-[2-(pyrrolidin-1-yl)ethyl]-1H-indazol-3-yl}ethynyl)pyridine-4-carboxylate

The title compound was prepared in 65% yield from Preparation 10a according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₂₂H₂₂ClN₅O₂, 424. Found, 424.

Preparation 20b: Methyl 2-{5-chloro-1-[2-(pyrrolidin-1-yl)ethyl]-1H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 39% yield from Preparation 20a according to the general procedure outline for Preparation 1d. Calc'd for C₂₂H₂₂ClN₅O₂, 424. Found, 424.

Example 20 2-{5-Chloro-1-[2-(pyrrolidin-1-yl)ethyl]-1H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 66% yield from Preparation 20b according to the general procedure outline for Example 1. ¹H NMR (400 MHz, DMSO-d₆): δ 1.91 (4H, br s), 2.67 (4H, br s), 3.62-3.77 (2H, m), 4.91 (2H, t, J=6.4 Hz), 7.56-7.65 (3H, m), 7.94 (1H, d, J=8.8 Hz), 8.42 (1H, s), 8.53 (1H, d, J=4.8 Hz), 10.54 (1H, s). [M+H] Calc'd for C₂₁H₂₀ClN₅O₂, 410. Found, 410.

Preparation 21a: Methyl 3-amino-2-(2-{5-fluoro-1-[2-(morpholin-4-yl)ethyl]-1H-indazol-3-yl}ethynyl)pyridine-4-carboxylate

The title compound was prepared in 59% yield from 5-fluoro-3-iodo-1-[2-(morpholin-4-yl)ethyl]-1H-indazole (See US Patent Application Publication 2014/171432) according to the general procedure outline for Preparation 1c. [M+H] Calc'd for C₂₂H₂₂FN₅O₃, 424. Found, 424.

Preparation 21b: Methyl 2-{5-fluoro-1-[2-(morpholin-4-yl)ethyl]-1H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylate

The title compound was prepared in 30% yield from Preparation 21a according to the general procedure outline for Preparation 1d. Calc'd for C₂₂H₂₂FN₅O₃, 424. Found, 424.

Example 21 2-{5-Fluoro-1-[2-(morpholin-4-yl)ethyl]-1H-indazol-3-yl}-1H-pyrrolo[3,2-b]pyridine-7-carboxylic acid

The title compound was prepared in 68% yield from Preparation 21b according to the general procedure outline for Example 1. ¹H NMR (400 MHz, DMSO-d₆): δ 2.67 (4H, br s), 3.02 (2H, br s), 3.59 (4H, br s), 4.76 (2H, br s), 7.46 (1H, t, J=8.9 Hz), 7.55 (1H, s), 7.61 (1H, s), 7.93 (1H, dd, J=9.2, 4.0 Hz), 8.12 (1H, d, J=8.9 Hz), 8.56 (1H, s). [M+H] Calc'd for C₂₁H₂₀FN₅O₃, 410. Found, 410.

II. Biological Evaluation

Example 1 In Vitro Enzyme Inhibition Assay

This assay determines the ability of a test compound to inhibit JMJD2C demethylase activity. Baculovirus expressed JMJD2C (GenBank Accession #BC143571, AA 2-372) was purchased from BPS Bioscience (Cat#50105).

JMJD2C Assay

This assay determines the ability of a test compound to inhibit JMJD2C demethylase activity. Baculovirus expressed JMJD2C (GenBank Accession #BC143571, AA 2-372) was purchased from BPS Bioscience (Cat#50105).

The ability of test compounds to inhibit the activity of JMJD2C was determined in 384-well plate format under the following reaction conditions: 0.3 nM JMJD2C, 300 nM H3K9me3-biotin labeled peptide (Anaspec cat #64360), 2 μM alpha-ketoglutaric acid in assay buffer of 50 mM HEPES, pH7.3, 0.005% Brij35, 0.5 mM TCEP, 0.2 mg/ml BSA, 50 μM sodium L-ascorbate, and 2 μM ammonium iron(II) sulfate. Reaction product was determined quantitatively by TR-FRET after the addition of detection reagent Phycolink Streptavidin-allophycocyanin (Prozyme) and Europium-anti-di-methylated histone H3 lysine 9 (H3K9me2) antibody (PerkinElmer) in the presence of 5 mM EDTA in LANCE detection buffer (PerkinElmer) at a final concentration of 50 nM and 1 nM, respectively.

The assay reaction was initiated by the following: 2 μL of the mixture of 900 nM H3K9me3-biotin labeled peptide and 6 μM alpha-ketoglutaric acid with 2 μL of 11-point serial diluted inhibitor in 3% DMSO were added to each well of the plate, followed by the addition of 2 μl of 0.9 nM JMJD2C to initiate the reaction. The reaction mixture was incubated at room temperature for 30 minutes, and terminated by the addition of 6 μL of 5 mM EDTA in LANCE detection buffer containing 100 nM Phycolink Streptavidin-allophycocyanin and 2 nM Europium-anti-H3K9me2 antibody. Plates were read by EnVisionMultilabel Reader in TR-FRET mode (excitation at 320 nm, emission at 615 nm and 665 nm) after 1 hour incubation at room temperature. A ratio was calculated (665/615) for each well and fitted to determine inhibition constant (IC₅₀).

The ability of the pyridine compounds disclosed herein to inhibit demethylase activity was quantified and the respective IC₅₀ value was determined Table 3 provides the IC₅₀ values of various compounds disclosed herein.

The ability of the compounds disclosed herein to inhibit demethylase activity was quantified and the respective IC₅₀ value was determined Table 3 provides the IC₅₀ values of various compounds disclosed herein.

TABLE 3 Chemical Synthesis JMJD2C Example Name IC₅₀ (μM) 1 2-(6-methoxy-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2- B b]pyridine-7-carboxylic acid 2 2-(5-methoxy-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2- B b]pyridine-7-carboxylic acid 3 2-(6-chloro-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine- B 7-carboxylic acid 4 2-[2-methyl-5-(trifluoromethyl)-2H-indazol-3-yl]-1H-pyrrolo[3,2- C b]pyridine-7-carboxylic acid 5 2-[2-methyl-5-(trifluoromethoxy)-2H-indazol-3-yl]-1H-pyrrolo[3,2- C b]pyridine-7-carboxylic acid 6 2-(5-cyclopropyl-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2- B b]pyridine-7-carboxylic acid 7 2-(5-chloro-2-methyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine- C 7-carboxylic acid 8 2-(6-chloro-2-ethyl-2H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7- C carboxylic acid 9 2-[6-chloro-2-(cyclopropylmethyl)-2H-indazol-3-yl]-1H- C pyrrolo[3,2-b]pyridine-7-carboxylic acid 10 2-{5-chloro-2-[2-(pyrrolidin-1-yl)ethyl]-2H-indazol-3-yl]-1H- B pyrrolo[3,2-b]pyridine-7-carboxylic acid 11 2-{2-methyl-6-[methyl(phenyl)amino]-2H-indazol-3-yl]-1H- B pyrrolo[3,2-b]pyridine-7-carboxylic acid 12 2-{2-methyl-7-[methyl(phenyl)amino]-2H-indazol-3-yl]-1H- C pyrrolo[3,2-b]pyridine-7-carboxylic acid 13 2-[1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7- B carboxylic acid 14 2-(5-fluoro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7- B carboxylic acid 15 2-[6-chloro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine- B 7-carboxylic acid 16 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7- B carboxylic acid 17 2-[6-chloro-1-ethyl-1H-indazol-3-yl)-1H-pyrrolo[3,2-b]pyridine-7- C carboxylic acid 18 2-[6-chloro-1-(cyclopropylmethyl)-1H-indazol-3-yl]-1H- C pyrrolo[3,2-b]pyridine-7-carboxylic acid 19 2-[6-chloro-1-(2,2,2-trifluoroethyl)-1H-indazol-3-yl]-1H- C pyrrolo[3,2-b]pyridine-7-carboxylic acid 20 2{5-chloro-1-[2-(pyrrolidin-1-yl)ethyl]-1H-indazol-3-yl]-1H- B pyrrolo[3,2-b]pyridine-7-carboxylic acid 21 2-{5-fluoro-1-[2-(morpholin-4-yl)ethyl]-1H-indazol-3-yl]-1H- C pyrrolo[3,2-b]pyridine-7-carboxylic acid Note: Biochemical assay IC₅₀ data are designated within the following ranges: A: ≦0.10 μM B: >0.10 μM to ≦1.0 μM C: >1.0 μM to ≦10 μM D: >10 μM

Example 2 In Vitro Cell-based Assay

The primary cellular assay for JMJD2C inhibition is an assay which measures cellular proliferation via Bromodeoxyuridine (BrdU) incorporation after 168 hours of compound incubation. Cell lines tested include the JMJD2C gene amplified cell line KYSE-150. This is a quantitative ELISA assay measuring DNA incorporation of BrdU during S-phase as a direct readout of cellular proliferation.

Assay Principle: This is a colorimetric immunoassay for the quantification of cell proliferation. Cells treated for 168 hours with test compounds are assayed for their ability to go through S-phase as a measure of their proliferative potential.

Assay Method: The human KYSE-150 (SMAD4 mut, TP53 mut) esophageal carcinoma cell line was seeded at 2,000 cells/well on a 96-well tissue culture treated plate. After an overnight incubation, cells were treated with compound in an 11-point dilution series with final concentrations ranging from 100 μM to 2 nM. Cells were then incubated in the presence of compound for 168 hours. After compound incubation the cells were assayed using a BrdU Cell Proliferation ELISA (Roche). The cells were first incubated with BrdU labeling reagent for 2 hours. After 2 hours, the BrdU incorporated cells were fixed and denatured, probed with an anti-BrdU-Peroxidase antibody for 1.5 hours and washed. Finally, a tetramethylbenzidine peroxidase substrate was added to each well for 15 minutes followed by a H₂SO₄ stop solution. The plate was read at 450 nm, and the raw optical density data was transferred into XLFit (IDBS) for IC₅₀ calculation using the formula: fit=(D+((Vmax*(x^n))/((x^n)+(Km^n))))

Table 4 provides the cellular IC₅₀ values of various compounds disclosed herein.

TABLE 4 Example Cellular IC₅₀ (μM) 10d D 11 A 16 D Note: Cellular assay IC₅₀ data are designated within the following ranges: A: ≦0.10 μM B: >0.10 μM to ≦1.0 μM C: >1.0 μM to ≦10 μM D: >10 μM

Example 3 In Vivo Xenograph Study

Time release pellets containing 0.72 mg 17-β Estradiol are subcutaneously implanted into nu/nu mice. MCF-7 cells are grown in RPMI containing 10% FBS at 5% CO₂, 37° C. Cells are spun down and re-suspended in 50% RPMI (serum free) and 50% Matrigel at 1×10⁷ cells/mL. MCF-7 cells are subcutaneously injected (100 μL/animal) on the right flank 2-3 days post pellet implantation and tumor volume (length x width²/2) is monitored bi-weekly. When tumors reach an average volume of ˜200 mm³ animals are randomized and treatment is started Animals are treated with vehicle or compound daily for 4 weeks. Tumor volume and body weight are monitored bi-weekly throughout the study. At the conclusion of the treatment period, plasma and tumor samples are taken for pharmacokinetic and pharmacodynamic analyses, respectively.

III. Preparation of Pharmaceutical Dosage Forms

Example 1 Oral Tablet

A tablet is prepared by mixing 48% by weight of a compound of Formula (I) or a pharmaceutically acceptable salt thereof, 45% by weight of microcrystalline cellulose, 5% by weight of low-substituted hydroxypropyl cellulose, and 2% by weight of magnesium stearate. Tablets are prepared by direct compression. The total weight of the compressed tablets is maintained at 250-500 mg. 

We claim:
 1. A compound of the structure of Formula (I),

or a pharmaceutically acceptable salt thereof, wherein, R¹ is hydrogen or alkyl; R² is hydrogen, halogen or alkyl; G is

n is 0, 1, or 2; R³ is alkyl, carbocyclyl, carbocyclylalkyl, heterocyclyl, or heterocyclylalkyl; R⁴ is halogen, alkyl, alkoxy, carbocyclyl, heterocyclyl, aryl, heteroaryl, or X—R⁵; wherein: X is —(C₁-C₆)alkylene-, —O—, —S—, or —NR¹—; and R⁵ is carbocyclyl, heterocyclyl, aryl, or heteroaryl.
 2. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein R¹ is hydrogen.
 3. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein R¹ is alkyl.
 4. The compound of claim 3, or a pharmaceutically acceptable salt thereof, wherein R¹ is methyl.
 5. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R² is hydrogen.
 6. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein the compound of Formula (I) is of Formula (Ia):


7. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein the compound of Formula (I) is of Formula (Ib):


8. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R³ is alkyl.
 9. The compound of claim 8, or a pharmaceutically acceptable salt thereof, wherein R³ is methyl.
 10. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R³ is alkyl substituted with at least one halogen.
 11. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R³ is carbocyclylalkyl or heterocyclylalkyl.
 12. The compound of claim 11, or a pharmaceutically acceptable salt thereof, wherein R³ is selected from a group consisting of:


13. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R⁴ is halogen.
 14. The compound of claim 13, or a pharmaceutically acceptable salt thereof, wherein R⁴ is chloro or fluoro.
 15. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R⁴ is alkyl substituted with at least one halogen.
 16. The compound of claim 15, or a pharmaceutically acceptable salt thereof, wherein R⁴ is —CF₃.
 17. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R⁴ is alkoxy.
 18. The compound of claim 17, or a pharmaceutically acceptable salt thereof, wherein R⁴ is methoxy.
 19. The compound of any one of claims 1-12, or a pharmaceutically acceptable salt thereof, wherein R⁴ is alkoxy substituted with at least one halogen.
 20. The compound of claim 19, or a pharmaceutically acceptable salt thereof, wherein R⁴ is —OCF₃.
 21. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R⁴ is carbocyclyl.
 22. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R⁴ is heterocyclyl.
 23. The compound of claim 22, or a pharmaceutically acceptable salt thereof, wherein the heterocyclyl is selected from a group consisting of:


24. The compound of any one of claim 1, or a pharmaceutically acceptable salt thereof, wherein R⁴ is X—R⁵.
 25. The compound of claim 24, or a pharmaceutically acceptable salt thereof, wherein X is —O—.
 26. The compound of claim 24, or a pharmaceutically acceptable salt thereof, wherein X is —S—.
 27. The compound of claim 24, or a pharmaceutically acceptable salt thereof, wherein X is —NR¹—; and R¹ is methyl.
 28. The compound of any one of claim 24, or a pharmaceutically acceptable salt thereof, wherein R⁵ is aryl.
 29. The compound of claim 28, or a pharmaceutically acceptable salt thereof, wherein the aryl is phenyl optionally substituted with halogen, —CN, alkyl, alkynyl, alkoxy, or carbocycle.
 30. The compound of any one of claims 24-27, or a pharmaceutically acceptable salt thereof, wherein R⁵ is heteroaryl.
 31. The compound of claim 30, or a pharmaceutically acceptable salt thereof, wherein the heteroaryl is pyridinyl optionally substituted with halogen, —CN, alkyl, alkynyl, alkoxy, or carbocycle.
 32. A pharmaceutical composition comprising a compound of any of the proceeding claim, or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient.
 33. A method for in vitro inhibiting a histone demethylase enzyme comprising contacting the histone demethylase enzyme with a compound of any of the proceeding claim in solution.
 34. A method for treating prostate cancer, breast cancer, bladder cancer, lung cancer and melanoma in subject in need thereof comprising administering to the subject a composition comprising a compound of any of the proceeding claim, or pharmaceutically acceptable salt thereof. 